The strike was to have begun at 5am this morning.

The Australian Manufacturing Workers Union, the Construction Forestry, Mining and Energy Union and the Electrical Trades Union called off the action yesterday after they struck an agreement on roster changes and pay.

The union had pushed for a 26-day on/nine-day off roster to be scaled back to 20-on/10-off, claiming it would be more family friendly, but the parties have reached a compromise of 23-on/10-off.

A 5% pay rise has already been agreed to for some of Australia's highest paid blue collar workers.

The deal averts what could have been several weeks of industrial action, which would have further hampered the already over budget and behind schedule megaproject.

CFMEU WA state secretary Mick Buchan described the 23/10 roster as "ground-breaking and industry-leading".

"This, in addition to the resolution of many other issues which have affected workers, is not just a massive victory for the workers on the Gorgon project but also sets new standards in the resource industry," he said.

Chevron welcomed the unions' decision to call off industrial action on Barrow Island, saying it hoped the final agreement would be finalised within days.

Gorgon is targeting first LNG before the end of the year, or early in the new year at the latest.

Chevron is building two massive LNG plants in Western Australia, Gorgon and the Wheatstone LNG project at Ashburton South, near Onslow.

It is unknown if Wheatstone workers will seek a similar deal when it comes time to renegotiate their contracts, further fuelling concerns about labour cost blow-outs in the sector.

Chevron Australia boss Roy Krzywosinski has previously expressed concerns about the lagging competitiveness of the LNG construction sector in Australia, low productivity and inflexibility in the labour sector.

He has long said that those factors threaten further LNG developments in Australia.