UPDATE 4-BP Alaska oil output down on maintenance, not fires

(Recasts with new BP comment, adds byline)

By Matthew Robinson and Robert Campbell

NEW YORK, Sept 12 (Reuters) - A sharp drop in BP's (BP.L: Quote, Profile, Research) Alaskan crude production this month has been caused by seasonal maintenance and not by a string of fires, the oil major said on Wednesday.

Alaskan government data shows output from BP's Prudhoe Bay field dropped to 186,000 barrels per day on Monday, down from over 300,000 bpd at the start of the month.

"The production profile for Prudhoe Bay is the result of normal field variability and planned maintenance activities," said a spokesman for the company.

Four accidents, including fires, at BP's Alaskan facilities over the past month have had only a small effect on output, the company said.

"The production impact from these events has been minimal, and falls within ordinary operational swings," BP Alaska said in a news release.

BP's operations in Alaska have been under intense scrutiny since a pipeline ruptured in March 2006, resulting in the worst spill on the Alaska North Slope.

Alaska officials said on Tuesday they were investigating the spate of fires.