Nigerian senior oil workers union and Chevron are expected to resume talks on Thursday in a last-ditch effort to avert an all-out strike that could sharply cut output from the world's eighth largest exporter.
Union workers have staged a partial strike this week, stopping administrative staff from getting to their offices in Lagos, to pressure management ahead of the two-day talks in Nigeria's capital Abuja.
Output has not been affected.
"I consider this a last attempt to avert a strike. If the talks fail, it shows that some are not sensitive to the plight and grievances of the workers," said Bayo Olowoshile, secretary general of the PENGASSAN union.
Olowoshile was optimistic the two sides would come to an agreement as a workers' strike would devastate Chevron's operations in Nigeria.
The company's output of around 350,000 barrels per day was reduced by a third last week when armed youths in the Niger Delta blew up one of its supply pipelines, a military source said.
Chevron has declined to say how much production was affected.
It declared a force majeure on its Escravos crude exports on Tuesday.
Fears of further supply disruptions in the West African country have contributed to a rise in global crude prices to near record highs.
The Chevron branch of PENGASSAN has been demanding the transfer of the expatriate managing director from Nigeria, accusing him of violating safety standards, having too many foreign staff and a lack of respect for Nigerian workers.
"There are too many expats," Olowoshile said.
"They have been here too long without building the capacity of the nationals to work in certain areas, especially mid-level and lower level management."
An eleventh hour intervention by the Nigerian government averted a workers' strike last week and brought both sides back to the negotiating table.
Chevron and the workers' union were expected to meet with Oil Minister Odein Ajumogobia on Thursday and with Abubakar Yar'Adua, group managing director of state oil firm the Nigerian National Petroleum (NNPC), on Friday.