(Adds gas production, trading source, details)
By Felix Onuah and Camillus Eboh
ABUJA, March 9 (Reuters) - Nigeria's petroleum minister said on Wednesday he would hold talks with trade unions to resolve a strike over restructuring at the state oil firm NNPC in Africa's biggest crude producer.
The protest did not affect the West African nation's oil and gas output, Sale Abdullahi, chairman of the PENGASSAN union at the NNPC section said, adding that workers had halted work at the Port Harcourt and Kaduna refineries, but oil insiders say both are not in production.
"It is not as if we want to ground the economy. No. That's not our intention," Abdullahi told Reuters when asked whether the union planned to shut down crude production.
President Muhammadu Buhari has prioritised reforming Nigeria's oil sector, long mired in corruption, as a sharp fall in crude prices has prompted the worst crisis in years in the continent's biggest economy.
On Tuesday, the minister, Emmanuel Ibe Kachikwu, who also heads the Nigerian National Petroleum Corporation (NNPC), said Buhari had approved a restructuring of NNPC into upstream, downstream, gas power marketing, refinery groups, and ventures divisions.
The Petroleum and Natural Gas Senior Staff Association of Nigeria (PENGASSAN) said 7,000 of its members, including refinery workers, petroleum tanker drivers and maintenance staff went on strike at midnight on Wednesday.
"The main reason for this is that we are in the dark. These changes have created real apprehension among our members," said the union's acting general secretary, Lumumba Okugbawa, adding that no decision had been taken on the strike's duration.
Kachikwu said he was "concerned" by the industrial action, which PENGASSAN said also included members of another union, and sought to clarify the changes.
"We did not unbundle NNPC, what we simply did was a reorganisation. NNPC has not been unbundled in the sense of breaking up NNPC into different institutions," he told Reuters, adding that the moves were a bid to provide proper stewardship.
"We are going to have a meeting with them right now. I don't want the industry shut down - I am going now to resolve the issues very soon," said the minister.
Workers closed the gates to the company's head office in Abuja as were seven NNPC fuel stations in the capital. There were also protests outside the Kaduna refinery, witnesses said.
NNPC mega stations in oil-producing Rivers and Bayelsa states are active but some independent marketers have shut down.
Trading sources said oil export loadings were going normally. (Additional reporting by Alexis Akwagyiram in Lagos, Tife Owolabi in Yenagoa, Garba Muhammed in Kaduna and Libby George in London; Writing by Alexis Akwagyiram and Ulf Laessing; Editing by David Evans)