By Alexis Akwagyiram
LAGOS (Reuters) - One of Nigeria's largest oil unions launched a nationwide strike on Monday over the laying off of its workers, its general secretary said.
The Petroleum and Natural Gas Senior Staff Association of Nigeria (PENGASSAN), whose members mainly work in the upstream oil industry, started the industrial action after talks with government agencies ended in deadlock, said Lumumba Okugbawa.
The move could hit the country's crude oil production and dent exports, as was the case in December 2016 during industrial action by the union against Exxon Mobil. Nigeria is Africa's largest crude exporter and oil sales make up two-thirds of government revenue.
"PENGASSAN is on industrial action as a result of unfair labor practices by some companies, particularly indigenous oil and gas companies," said Okugbawa.
The dispute arose after domestic oil and gas companies and marginal field operators laid off members of the union. Marginal fields refer to discoveries made by oil majors during exploration of larger acreage but which have been left for others to develop.
The union leader said office workers and staff working in distribution were among those taking part in the strike. He did not disclose the estimated number of workers involved and Reuters was not immediately able to ascertain the impact of the strike.
Nigeria's crude production has fluctuated over the last two years due to militant attacks, pipeline theft and industrial action.
(Editing by Louise Heavens, editing by Louise Heavens)