Oil workers for Esso in Chad were on strike from Tuesday to Thursday in protest that they are paid less than colleagues in Cameroon, where Chadian oil is pumped for export by the Exxon Mobil-led consortium, strikers told AFP .

"The oil comes from Chad but Cameroonian workers are better paid than us. We will not accept this discrimination," workers' representative Mahamat Saleh Adoum told AFP .

The 420 workers have listed their demands to management but no response has been given yet, Adoum said.

"We are aware that the three day strike can't have affected production but if our employer refuses to talk we will stage long term action," Adoum added.

Esso Chad declined to comment when contacted by AFP.

The oil field contains an estimated one billion barrels of oil, which is extracted at a rate of around 200,000 barrels per day.

Alongside Exxon Mobil, the other consortium members are fellow US oil group Chevron and Malaysia's Petronas.