British oilfield services company Petrofac Ltd. said BP had awarded it a contract worth about $800 million for the second planned phase of the Khazzan gas field in Oman.

The contract involves work to help drive an increase in total production capacity from the central processing facility to 1,500 million standard cubic feet per day, Petrofac said.

Petrofac also worked on a $1.4 billion project for the first phase at the Khazzan project.

BP said in September it had begun production at the Khazzan gas field, the sixth and largest of seven new upstream projects that were due to start for the British oil giant this year.

The oil major said then that about 300 wells were expected to be drilled over the lifetime of the Khazzan field, adding that the two planned phases would develop an estimated 10.5 trillion cubic feet of recoverable gas resources.

"The successful start of production from Khazzan Phase 1 was a major milestone for BP in 2017. We are now building on this, deepening our partnership with the Sultanate of Oman...," said Bernard Looney, CEO Upstream at BP.

BP, which has had an upstream presence in Oman since 2007, is lead partner in the project with a 60% interest. Oman Oil Company Exploration & Production holds 40%.

Petrofac's shares were up 3.7 percent at 451 pence at 1544 pence, making it the top gainer on the FTSE Midcap Index.