SHE’s late, but she could have been a lot later. “Christ, I’m sorry,” said Elle Macpherson. “I had it down for next week. I just had to throw something on and rush out.”

I am 6ft 2in and she towers above me, all in black, three-inch heels, long-armed, long-legged, like a glamorous tarantula.

“Sorry,” she continued, taking in the room where I was waiting - a camp concoction of zebra-skin pouffes and glitzy clothes, from the latest collection by Roberto Cavalli. She and Cavalli share the same PR firm, where we met. “Wow,” she said. I asked her if she liked Cavalli. “Yeah, mate,” switching to broad Australian, “but I’m only interested if it’s comfy and looks nice.”

Macpherson, supermodel-turned-lingerie queen, has made that her leitmotif. Her Elle Macpherson Intimates range is now the biggest-selling brand of fashion lingerie in Britain, and it’s heading that way in America too.

Launched 17 years ago in a low-key venture with New Zealand-based manufacturer Bendon, it offers designer underwear in a range of styles, from £10 thongs and £30 contour bras to £70 basques and £85 nighties. Pitched above mid-market, Elle Macpherson Intimates now bestrides the globe - well, almost. It’s not in Russia and China, and Macpherson’s men’s range (available in Australia and New Zealand) has yet to be launched here.

Why not? “That’s a question you should ask Bendon,” she said, waggling her eyebrows suggestively. She wants them to move faster. She has plans for a younger line, Ms Mac, and would love a flagship store in London. This business is not stalling for want of Macpherson pushing.

And she takes it seriously. “What we create is lingerie for all body types. And as I’ve got older, my designs have become more interesting. As my body shape has changed, so the proportions of my bras and knickers have changed, according to what works for me today.”

This is more than endorsement. Bendon manufactures, ships and sells, while Macpherson advises, approves and promotes. She also controls design, and signs off every product. She is paid a licence fee and a cut of the profits thought to run into millions of pounds.

It helps that she is an underwear junkie. Bendon executive chairman George Brooks laughed when I called him in New Zealand – he said the company had just received a shipment of underwear “bought by Elle”. She trawls the shops, picking up rival brands, new fabrics, new designs, letting Bendon’s designers know what she likes. Macpherson is totally immersed. “I have been passionate about underwear since I was a little girl,” she said.

It’s hard to believe she was ever little. Six-foot tall by the age of 16, brown-eyed, big-bosomed and lithe-limbed, she started as a model in Australia before moving to America at the age of 18, and becoming one of the most famous bodies in the world. Films and television followed.

And she is still a knockout at 43: chiselled and shapely, with long dark hair hanging straight, and the carriage of a 30-year-old. Yet the sexiest thing about her is her attitude: no smouldering, no simpering – just blunt and unpretentious, as you might expect from a self-proclaimed “Aussie surfer chick” now at large in London.

Her relationship with her looks is, I would guess, more complex than an Aussie shrug. She moans about how long it takes to prepare herself for photo sessions, but she still does them; she hates being noticed, but despite her height she still puts on three-inch heels. She even tells me she rarely goes out, but such a statement contradicts the gossip magazines. That’s because she is her brand, and she has to represent it constantly. It was a decision she took early on, and her reasoning reflects her ambivalence about the modelling world. “I understood the only way to justify what I was doing was if I capitalised on the commercial recognition,” she said.

Is she driven by money? She frowns. “No, I do this because of the opportunity to express myself, to create fashions, to be exposed to opportunities, so I can have some interesting choices.”

She doesn’t sit at the top of a company giving orders, though – instead, she has a tight team round her, including her Australian manager Stuart Cameron and the London lawyer Alexander Carter-Silk, who keep the wheels of her relationships with Bendon and others turning. She has seen six bosses come and go at Bendon, and has renegotiated the terms of the licence more than once.

That means there must be tensions. Bendon boss Brooks tells me they would like to push the brand into more countries but they don’t have the licence deal to do so – because Macpherson won’t hand it over without negotiating a deal. She is no pushover.

“It is so tricky,” she said. “There is always tension, minimum guarantees that have to be met. I don’t do licensing any more, I do equity.” By equity, she means she wants to own bits of the companies that use her name to sell products. “Her business value is much greater now,” said Carter-Silk, “so she has the ability to say, ‘Royalties are all very well, but I want a percentage share’.”

Lingerie is just the start of a mooted Macpherson empire. She has a cosmetics brand, the Body, with beauty specialist Meller Beauty, the developer behind the Normandie Keith line selling at Tesco.

She also hints at an internet plan. “The internet is the modern way of retailing – but I can’t say any more.”

More clothes? She gives a throaty laugh, then stares: “You can write, ‘She was strangely silent, with a smile’.”

Cameron said Macpherson was different from the other models on the circuit: smarter, tougher and never part of the clique. “She had an eye to carve out a different career, which some of her contemporaries thought a bit silly,” he said. “Bet they regret that now.” And she has become more intense about business, he said, since becoming a mother.

She has two young sons by her former partner Arpad “Arki” Busson, a French-Swiss financier. Being a single mother, and travelling to promote your brand – isn’t that a stretch? No, said Macpherson, suddenly steely: she has the children one week, their father has them the next – that gives her time to focus on business. She also has a team of assistants, mainly Aussies, mainly women.

Don’t other women see her as threatening? She looked appalled at my question. “I have incredible respect for women – my products are made for them.”

And the work ethic? “Oh, my parents were always working, and there’s a bit of that in me,” she said. Her father was a sound engineer who set up a string of franchised audio shops in Sydney. Her mother was a nurse who gave up her job to help him; she was only 16 when she had Elle. “My dad is seven generations Australian with a bit of Aborigine mixed in; my mum is Irish, English, Danish, French,” said Macpherson. “My dad was driven. He loved what he did, and he was a perfectionist.”

Macpherson’s parents divorced when she was 10, and she moved with her mother and two siblings. Her mother remarried, and a mistake registering at a new school meant she lost her father’s name, Gow, to her stepfather’s, Macpherson. How does her father feel about that? “It was unintentional. He’s mature enough to understand. I have a great relationship with him, and he’s an amazing grandfather.”

There is a restlessness to Macpherson that you can feel even sitting with her – the legs crossing and uncrossing, the long arms going here and there, always fiddling with her bangles. When she was a kid she poured that into swimming. “I trained every morning from 5am, and the days I didn’t train I was moody,” she said.

Her insecurity was about being different. “Because I was tall . . . my parents were divorced – no child wants to be different.” Yet she fell into modelling after betting a girlfriend that nobody would take her on. Later, she won a talent competition run by the Ford agency that took her to America. It cost hera place at university, reading law.

She started making so much money in America that she didn’t think it was worth going back.

But eventually her unease at modelling took her into the arms of a French husband, the photographer Gilles Bensimon. Did he protect her? “I married young because he was an interesting, creative, passionate man. He didn’t protect me. But did I go home and cook dinner for my husband at night rather than do nightclubs and heroin? Yes.”

They later divorced, but she credits him with educating her – music, museums, wine, food and the fashion business. He also gave her the confidence to take control of her own career. Early on, after her success in Sports Illustrated, she made her own calendar of swimwear shots: “Cost me $30,000; I made $120,000.” By the time Bendon approached her 17 years ago, asking if she wanted to endorse its swimwear range, she was up for a different challenge. She suggested lingerie instead, for a cut of sales, not money upfront. And she would design it. From that, the business was born. And she was smart, say advisers, in getting it right in Australia and New Zealand for 10 years, before bringing it to Britain and America.

Is she a control freak? She laughed. She is often accused of it, but if you are operating in business, it’s pretty stupid to abrogate control to others, she said. And if she were a control freak, she would be more bothered by the gossip about her love life. The range of mooted boyfriends is extraordinary, from Colin Farrell to Al Pacino. She giggles when I bring it up – some, she said, she hasn’t even met.

Is it difficult to have a private life? “No,” she said. “My experience is that if the intention is for discretion, nine times out of ten, you can achieve it. Some people believe the more they are in the magazines, the more successful they are, but it is more complicated for me.” Complicated because she represents a business, and must be seen.

Then she added: “You know, I am not one to say, ‘Woe is me, all the attention I get’.” And she pulls a face as if to say, get over it.