The Calgary, Alberta-based company said it is trying to reach an agreement with Masila Labour Union and government agencies.

Last Wednesday workers on the company’s Hadramout oilfield went on a brief strike.

They agreed to remain at their jobs for five days while talks continue toward a more permanent accord, the union spokesman said.

Nexen, which also has operations in Canada, North Sea and the Gulf of Mexico, said it is currently operating at reduced rates at its Buzzard field in the UK North Sea due to problems with the field’s cooling system.

Buzzard is a major contributor to the Forties oil stream, which usually sets the dated Brent crude oil benchmark used in Europe, Asia and the Middle East to price cargoes.

About half of Nexen’s oil production comes from its North Sea holdings while Yemen accounted for about 12.4 percent, according to Reuters data.