LAGOS, Nigeria (AP) - In oil-rich Nigeria, where tycoons race Italian sports cars down potholed roads and rents get paid years in advance, the minimum wage sits at only $50 a month.

Labour groups say such wages cripple those working in Africa's most populous nation while legislators and top officials receive salaries and perks often exceeding those in Western countries. Upset by the minimum wage, trade unions took to Nigeria's streets Wednesday as part of a warning strike to bring the government in line with a promise to boost the minimum wage to $150 a month.

By Wednesday afternoon, the union leaders told journalists in Abuja they would end the strike at midnight after receiving assurances from the president to raise the minimum wage. They held out the possibility of a prolonged strike if the government does not act.

However, activists warn even $150 is too low to support families in major cities like Lagos, as inflation continues to chew away at earnings.

"Our struggle is just not about minimum wage; our struggle is also about the strategy driving the economy," said Abiodun Aremu, a labour organiser in the city of 14 million.

Nigeria reaps billions of dollars a year in oil sales, with much of the easily refined crude being shipped to the US to supply its voracious appetite for gasoline. Much of that money gets funneled into federal and state budgets in a nation routinely described by analysts as one of the world's most corrupt. Meanwhile, roads remain rutted and power comes in fits.

World Bank statistics suggest more than 80 percent of people in Nigeria, a country home to 150 million, earn less than $2 a day. Many find employment through petty trading, farming and the odd jobs that populate the nation's largely unregulated employment market.

Former President Olusegun Obasanjo increased minimum wages for government employees in 2000 to 7,500 naira - about $75 at the exchange rate then. The rate has plummeted since, with the same amount of naira now worth about $50. Those wages carry even less value as inflation, pegged at 12.4 percent last year alone, cuts into earnings.

Despite last-minute negotiations by President Goodluck Jonathan, the Nigerian Labour Congress and the Trade Union Congress launched the planned three-day strike on Wednesday. At Lagos' Murtala Muhammed International Airport, local airlines reported union employees had disrupted flights. Streets in Lagos saw few cars and buses running in motorways typically gripped by gridlock during daylight hours. Banks and other businesses sat closed.

"Our conscience is clear," said Peter Esele, the leader of the Trade Union Congress.

A group of labour union activists took to the streets of Yaba, a Lagos neighbourhood, waving signs on Wednesday calling for higher wages and urging the public to "Defeat Capitalism B 4 It Kills Us". However, life went on for the petty traders working along the neighbourhood's narrow streets, selling mobile phone charges, bras and food. Some even proffered photos showing curtains for sale.

At a shop selling luggage, a 57-year-old man who called himself Bernard watched the activists march down the street before shrugging and turning back to his wares.

"There's plenty of money in Nigeria," he said. "Nigeria has oil. Nigeria has everything...But we're just managing to survive."