A major oil union in Nigeria says it will go on strike beginning Sunday if the continent's top oil-producing country does not restore a popular consumer fuel subsidy.

The Petroleum and Natural Gas Senior Staff Association said Thursday it would be forced to take “the bitter option” of shutting down oil and gas production if the government does not meet its demand.

Nigeria exports more than two million barrels of crude oil a day and a major disruption could have an impact on the country's economy and affect global oil prices.

President Goodluck Jonathan was meeting with union leaders at the home of the chief of the senate in Abuja on Thursday.

If the oil union goes on strike, it would join two major trade unions that launched a nationwide strike on Monday, prompting tens of thousands of Nigerians to stage protests that have paralyzed major cities.

Many businesses, shops and schools remain closed on Thursday as demonstrations continued for a fourth straight day in the commercial capital of Lagos and other cities.

President Jonathan and his government eliminated the fuel subsidy on January 1, saying the nation can no longer afford the $8 billion program. The move caused full prices to double in a day.

Mr. Jonathan has promised to use the money on infrastructure and social programs.

Most Nigerians live on less than $2 a day and the fuel subsidy was one of the few benefits they received from the country's oil wealth.

Some economists have charged the subsidy was wasteful, but protesters have alleged that government corruption and mismanagement are responsible for the oil-rich nation's sustained poverty.

While Nigeria is Africa's biggest oil producer, it must import refined fuel because its own refineries do not have the infrastructure to do the job.