US oil output hit by post-spill project delays-IEA

* Delays already trim U.S. oil output by 30,000 bpd

* Extended delays could cut 2015 projection

LONDON, July 13 (Reuters) - Delays to new oil projects in the Gulf of Mexico following the BP Plc (BP.L> oil spill are already reducing production, the International Energy Agency said on Tuesday.

Delays have trimmed 30,000 barrels per day (bpd) from estimated United States crude production this year and next, the IEA, adviser to 28 industrialised countries, said in its monthly Oil Market Report.

The forecast from the IEA followed the announcement of a new six-month moratorium on deepwater drilling in the Gulf of Mexico, replacing an earlier ban that had been struck down by U.S. courts. [ID:nN12269656]

"Until more clarity prevails over new regulatory and operating procedures and whether the deepwater drilling moratorium will stay in place, we refrain from including a broader downward adjustment to our U.S. production forecast," the IEA said.

The agency added, however, that extended project delays should they occur could reduce its 2015 projection for U.S. Gulf production by 100,000 bpd to 300,000 bpd.

BP has so far been unable to stop the oil leaking from the Macondo well since the April 20 explosion on a drilling rig, although it has been capturing some of the flow.

"We estimate that something in the range of 2.3 to 4.5 million barrels of crude oil have been spilled in total, excluding the volumes contained, making this the largest oil spill in U.S. history," the IEA said.

BP was preparing on Tuesday to try sealing off the well with a new cap that it says could finally arrest the flow of oil. [ID:nN13221621]

For a story on the IEA's global supply and demand outlook, see [IDn:LDE66C0PP] (Reporting by Alex Lawler; editing by William Hardy)