The long-term deals are rare in Qatar's oil and gas sector and cover engineering and maintenance services, when the plant starts production.

Among the companies understood to have prequalified for potential deals are the UK's Amec, Petrofac and Production Services Network (PSN), formerly a division of the US' KBR, and Halliburton, also of the US.

It is thought that up to four integrated agreements will be signed with Pearl GTL over the coming months as Shell aims for the next stage of the facility's development.

One executive close to the talks says the deals could last in excess of five years and have attracted strong interest from the contractor community.

"The Pearl development is one of the biggest in the region so there is plenty of work available going into the next decade," says the executive.

The deals would be some of the last in a series of awards on Pearl, with about $10bn worth of contracts already handed out.

The last major energy maintenance deal was signed in 2004 between Ras Laffan Liquefied Natural Gas Company (RasGas) and a joint venture comprising Transfield Services and WorleyParsons, both of Australia, and the local Trags (MEED 5:11:04).

PSN, Amec and Petrofac were unavailable for comment.