UPDATE 4-French union mulls refinery strikes over plant closure

* General meetings in all French refineries on Wednesday

* Berre refinery workers voted for a 48-hour strike action

* Company plans to continue petrochemical operations

* Refinery operations shutdown will affect 370 jobs (Adds CGT official, LyondellBasell comments)

By Jean-Francois Rosnoblet and Muriel Boselli

MARSEILLE/PARIS, Sept 27 (Reuters) - The powerful CGT trade union will on Wednesday discuss possible strikes at refineries across France, recalling a month-long stoppage a year ago that altered global flows of crude oil and liquid fuels.

A CGT official said workers at Lyondellbasell's > Berre l'Etang refinery voted on Tuesday to strike after the group announced the plant's closure.

They would hold a 48-hour strike at the 105,000 barrels-per-day plant in southeastern France, after which there would be successive votes on whether to prolong the stoppage there, the official said.

"All operations at the refinery will stop and we will block all access to ensure no products come in or out," he said.

A spokesman for LyondellBasell said the timing of the refinery's closure would be addressed during a consultation process due to begin in October.

Another CGT official told Reuters: "There will be general assemblies at all of France's 10 refineries following what happened at Berre today."

Strike calls could be part of those discussions, he added.

He added that CGT union officials of the four refineries based in the Berre industrial site would also meet on Friday to discuss possible strikes. Total , Ineos and ExxonMobil , also run refineries on the site.

French refinery workers blocked production for a month in October 2010 to protest against a government pension reform. The strike cost the oil sector 230 million euros, France's oil lobby said.

Earlier in 2010, Total's move to close its Dunkirk refinery triggered a 2-week strike at all of the major's French refineries.

LyondellBasell, a Rotterdam-based commodity chemicals maker, said earlier on Tuesday it planned to close the refinery, affecting some 370 jobs, after the search for a buyer it announced in May had proved unsuccessful.

"Divesting the refinery would help us to focus on our core petrochemical assets at Berre and would preserve approximately 900 jobs supporting the petrochemical assets," the LyondellBasell spokesman said in an email.

"The refinery has suffered significant losses over the past three years. The economic situation of the refinery has continued to worsen this year," he added.

Union officials said the company had told them the refinery had triggered losses of 400 million euros ($538 million) since 2008 and projected it would lose up to 140 million euros in 2012.

Shares in LyondellBasell, which is primarily run out of Houston, Texas, were up 4.5 percent at 1635 GMT, outperforming the Dow Jones index which was up 2.4 percent.

The European refining sector has been struggling for several years due to poor margins and weak demand for fuel products.

The sector is coming under increasing pressure from new competitors, particularly in the Middle East, which have an advantage in accessing crude feedstock.

Last week oil major Total summoned a group works council meeting for Oct. 10 to unveil a project to merge its refining and chemical businesses to make them more efficient, saying the move will not involve layoffs. ($1 = 0.742 Euros) (Additional reporting by Divya Sharma in Bangalore and Sybille de la Hamaide in Paris; editing by Anthony Barker)