"My mother would not pay what I pay for shoes," said Okoro, a Nigerian professional in her late 30s as she prowled the sleek Westgate shopping mall in her adopted home of Nairobi.

"At my age, my mother had nine of us. The reality for Africa is that we are the new breed," she said. She spends an average of about $500 a month on clothing and shoes - a breathtaking sum in the world's poorest continent.

Although millions of Africans remain stuck in crushing poverty, the fast-growing continent is no longer defined solely by privation and disease. Luxury brand sellers are targeting the small but increasingly visible number of what South African retailers call "black diamonds", or affluent African professionals.

Their mushrooming aspirations for Hugo Boss suits, Prada sunglasses and Louis Vuitton purses is reminiscent of India and China more than a decade ago, experts say, although Africa still has a long haul to match Asia's roaring demand for bling.

Africa's population of people whose fortunes are large enough to qualify as "high net worth individuals" was the fastest growing in the world in 2009-2010, according to the latest annual report from Merrill Lynch and Capgemini.

Of course, an exclusive band - usually of government elites - have for decades shopped in London, Paris and New York. Rising disposable incomes and the development of shiny new malls mean more Africans can now buy their luxury at home.

Sub-Saharan economies are among the fastest growing in the world. The region itself is expected to average 6 percent growth this year, driven by continued demand for oil and minerals.

Besides national commodity wealth, in South Africa many with ties to the ruling African National Congress have benefited from lucrative government contracts, or tenders, spawning a brash new elite known as "tenderpreneurs".

But serious money is still concentrated in the hands of a lucky few, meaning many buyers of luxury brands in Africa are "aspirational consumers," or shoppers who will splurge on a product even when they may not be able to afford it.

TAKING ON DEBT

"I'm not rich, but I have a few Gucci jeans," said David Zwane, a South African chartered accountant shopping in Sandton City, suburban Johannesburg's flagship upmarket mall.

"Rich is when you are able to eat sushi off half-naked women's bodies and pour expensive champagne on a crowd of people," he said, referring to a birthday party thrown by one South African businessman who was photographed in the media doing just that.

Dressed in a trim Lacoste T-shirt and fashionable jeans, Zwane said he had spent 10,000 rand on a silver Mont Blanc bracelet for his wife's Christmas present.

Africa's infatuation with expensive luxury brands is most visible in its cars: the potholed streets of Nairobi, Lagos and Johannesburg's Soweto township are increasingly home to Audis, BMWs and Mercedes-Benz.

Many consumers pay for big-ticket items with credit, which could pose a risk to the economy. "Luxury goods are a status symbol for Nigerians," said Edwards Efe, a 42-year-old telecom executive shopping for a Swatch watch and Polo cologne at The Palms, a shopping centre in Lagos.

"It doesn't have to do with your income, it has to do with the taste and class you want to associate with and that's why you find that sometimes we borrow to finance these things."

South Africa's central bank has repeatedly warned that debt levels are too high in the continent's biggest economy. Household debt currently stands at 75 percent of disposable income, the South African Reserve Bank said in December. For comparison, in Brazil, this ratio was 42.5 percent in October 2011.

On average, South Africans spend 7 percent of their disposable incomes just on servicing their debts. During a 2009 recession, banks were hit hard by ballooning bad debts at vehicle finance units.

LONG-TERM MARKET

Isabel Cavill, an analyst with research firm Planet Retail in London, expects affluent shoppers to continue to multiply in Africa, but much more slowly than in China and India: "We're looking at this as a very sort of long-term development."

For local shop managers, the steady growth in recent years has been noticeable. As recently as five years ago, some high-end stores in Johannesburg's Sandton City mall could go a full day without selling anything, according to several managers who spoke to Reuters. That's not the case now.

"We are seeing more and more people coming to shop. On average we get 30 customers per day," said one manager at the Sandton City branch of an international fashion house. But she added that less than half the visitors actually buy something.

Even smaller countries that are still reliant on foreign aid, such as Senegal, are starting to see more lavish shopping habits.

Dakar, the west African country's capital, is home to the $35 million Sea Plaza mall, opened in 2010, and the nearby Radisson Blu luxury hotel. The work of media-shy Senegalese businessman Yerim Sow, both sites have become top attractions and draw as many as 4,500 visitors on a busy day.

Part of Sow's idea behind Sea Plaza was to dispel the misconception that top-end commercial retail centres cannot succeed in sub-Saharan Africa, said Cheikh Saadbou Niang, the mall's head of administration.

Sea Plaza is home to fashion labels such as Hugo Boss, Mango and Guess, as well as haute couture apparel shops and high-end electronics stores. "It is like the Champs Elysees right here in Dakar," said one shopper walking to his car, trailed by a shop assistant carrying a 40-inch flat screen television.

OVERLOOKED COUNTRIES

In addition to Senegal, German fashion house Hugo Boss has established a presence in several other African countries that have been so far been overlooked by big-name global retailers such as Mozambique, Angola and Ivory Coast.

The brand has four stores in South Africa alone. Nearly 80 percent of the customers who visit its Sandton City branch are "black diamonds", reckons Surtee Sulimann, a brand manager.

"Some of them can spend $24,000 without blinking an eye," he said. "And we get a lot of people from Nigeria and Angola."

Other retailers are joining in. Zara, the popular label of Spain's Inditex, opened its first sub-Saharan store, in South Africa, late last year. Cape Town-based retailer Woolworths, which is similar in style and products to Britain's Marks and Spencer's, is aggressively ramping up its presence on the continent.

It aims to double the number of its African stores outside of South Africa to 120 by 2014, Chief Executive Ian Moir said last month. Target countries include Nigeria, Uganda, Mozambique and Kenya.

INFRASTRUCTURE AND CORRUPTION HURDLES

But global retailers face plenty of hurdles in Africa, particularly from the continent's notoriously poor infrastructure and widespread administrative corruption.

"It is very difficult to set up business in Africa, it's very difficult to import goods into Africa," said Joelle de Montgolfier, a director in Bain & Co.'s retail and luxury practice. "Once you get goods into ports, it's very difficult to get them out."

Africa's luxury market will face significant challenges to see anything close to the expansion of China's, de Montgolfier said. "China is a very unified market and Africa is 57 markets with different regulations. It's a bit more complex to do business in Africa."

That won't deter the millions of Africans who want to show off their new-found wealth, or at least look like big spenders. Many poorer South Africans buy counterfeit goods - fakes from Hong Kong known as Fong Kongs - that are sold on almost every street corner in major cities.

"I love Louis Vuitton bags but I can't afford the real thing," said a man dining at an upscale fast food restaurant in Soweto's Maponya Mall who gave his name as Mpho.

"It looks just like the real thing, but it's a 'Fong Kong.'"

(Additional reporting by Chijioke Ohuocha in Lagos, and Bate Felix in Johannesburg; Writing by David Dolan; Editing by Pascal Fletcher and Sara Ledwith)

• A Permanent Economic Emergency