By Tom Finn
DOHA, May 25 (Reuters) - Six international oil firmsincluding BP and Royal Dutch Shell Plc have bidto operate Qatar's largest offshore oil field, two people withknowledge of the matter told Reuters.
The other bidders are the field's current operator Maersk, as well as Total SA, Chevron Corp and ConocoPhillips, said the people who spoke oncondition of anonymity as the information was private.
The people said state-owned Qatar Petroleum (QP) would awardthe contract for the oil field, which is 80 kilometres (50miles) off Qatar's coast and currently produces around 300,000barrels per day (bpd), in the second half of the year.
Officials at Maersk, Chevron, Conoco and Qatar Petroleum didnot immediately respond to requests for comment.
Shell and BP declined to comment.
A Total spokesman said CEO Patrick Pouyanne had confirmedits bid earlier this month.
Denmark's A.P. Moller-Maersk, which owns Maersk Oil Qatar,said on May 4 it was involved in a tender process and there wasa risk it could lose the Qatari field, its largest oil producer.
For years it was expected Maersk would renew its 25-yearproduction agreement on Al Shaheen field when its licence runsout in 2017.
But the Gulf state surprised the company last year byputting out a tender for the field which Maersk Oil has beenoperating since 1992.
A Qatari oil source told Reuters the Gulf state had invitedinternational majors to the tender because it wanted to raiseproduction at the field to 500,000 bpd.
Maersk Oil had originally planned for Al Shaheen'sproduction to reach 525,000 bpd by 2010, after a 2005 fielddevelopment plan was approved, but output remained at about300,000 bpd, roughly half of Qatar's daily crude output.
The oil reservoirs are notoriously thin and spread outacross a vast area, making production difficult.
BP withdrew from a $4.3 billion project to build Qatar'sfirst liquefied natural gas (LNG) plant in 1992, stating it sawno financial benefits to staying in the project.
Since then, Qatar, a country of 2.6 million, has gone on tobecome the world's richest by per capita income and the largestproducer of LNG, which is gas chilled to liquid for export onspecially designed ships.
A senior BP company executive told Reuters in 2007 it waseyeing a return to Qatar's upstream gas sector after a 15-yearhiatus and was interested in offshore exploration areas andtaking part in projects to produce more difficult gas reservesin Qatar. (Additional reporting by Ron Bousso in London and Bate Felix inParis; Editing by Mark Potter)