State-owned energy company Saudi Aramco is bringing forward the deadline for the main construction packages on its planned 400,000-barrel-a-day (b/d) Yanbu export refinery to 26 January, from 31 January.

A source at one contractor bidding for work at Yanbu says the change to the deadline was made in early December without explanation.

In June, the joint venture of Aramco and US oil major ConocoPhillips invited 29 prequalified international contractors to bid for the five largest engineering, procurement and construction packages on the Yanbu refinery, worth more than $5bn in total.

The five packages are a $1.2bn coker unit, a $970m crude facility, a $2.3bn gasoline unit, a $1.2bn hydrocracker and a $900m tank farm.

The $10bn export refinery at Yanbu is one of the largest downstream energy projects to be tendered in the Middle East in 2009.