RIYADH, (Reuters) - Saudi Aramco said on Sunday it would start developing the Moneefa oilfield in the first quarter of 2007 to add 900,000 barrels per day of Arab Heavy crude by mid-2011.

Moneefa is also expected to produce 120 million cubic feet per day of gas, the state oil firm said in a statement.

Saudi Arabia, the world's top oil exporter, has fast-tracked oilfield expansion plans to boost output capacity to meet rising world demand and maintain a spare production capacity of at least 1.5 million bpd.

The kingdom plans to boost its crude oil production capacity to 12.5 million bpd by 2009 from 11.3 million bpd. For the Moneefa project, Aramco said a lump-sum turnkey contract for a 41-km (25.5-mile) causeway was expected to be awarded by year-end. The project also includes onshore oil and gas facilities and deeper water offshore drilling facilities.

"The causeway is the critical first step for this project, as a significant number of the Moneefa development's wells are in shallow offshore areas that are not conducive to the traditional use of ocean vessels to set up the jackets and platforms," Aramco said.

It said bidding for the front-end engineering and design contract of the onshore portion of the programme closed on Sept.26 and would be awarded in late October. Engineering work is expected to be completed in the fourth quarter of 2007.

The offshore lump-sum bid packages are expected to be awarded in early 2007, Aramco said.