SYDNEY - Workers at Chevron's two major liquefied natural gas (LNG) projects in Australia are set to begin total strikes for two weeks from Thursday, potentially disrupting output that accounts for more than 5% of global supply.

Australia is the world's biggest LNG exporter and its main buyers are in Asia. Traders anticipate any cuts to supplies would intensify competition, with Asian buyers competing with Europe for cargo, spurring spot price volatility in the European gas market.

Research group EnergyQuest estimated revenue at risk for Chevron and partners from the strikes at about A$76 million ($49 million) per day, though it said not all of the revenue would be lost as some cargoes may be deferred to a later date.

The union alliance, which had previously said the strike would begin at 6 a.m. Perth time (2200 GMT on Wednesday), did not immediately respond to a request for comment. Chevron has said its focus will be on maintaining reliable operations if disruptions occur.

Brief work stoppages began last week after talks broke down over ongoing disputes on wages and conditions at the U.S. energy major's Gorgon and Wheatstone operations. The unions had said they would escalate to a total strike until Sept. 29, although they have discretion over how long they actually stop work.

In a bid to stop industrial action, Chevron is pursuing an untested legal strategy and has applied to the Fair Work Commission, Australia's industrial arbitrator, for an "intractable bargaining" declaration. If granted, it would end the strikes and allow the umpire to dictate an agreement.

The tribunal will hold its first, and so far only, hearing on Sept. 22.

Dutch and British wholesale gas prices rose slightly on Wednesday ahead of the planned strikes as lower demand in Europe and high gas storage levels curbed appetite.

Goldman Sachs said in a note that the 24-hours a day strikes will raise supply risks as any outages likely require specialised workers onsite for a fix, although chances of a long outage that could fuel a lengthy spike in gas prices were low.

"This is both because of the potentially large revenue losses to Chevron, the facility operator, associated with a full LNG export outage, and because of potential regulatory intervention," Goldman analysts said in a note.

($1 = 1.5571 Australian dollars)

(Reporting by Renju Jose in Sydney; Editing by Jamie Freed)