UPDATE: Valhall Field Back Online, Ramping Up - BP

BP PLC (BP.LN) Thursday said it has restarted its Valhall field in Norway after an extended outage to check and repair microbial-induced corrosion on pipelines at the field.

"We are back on stream, started carefully Sunday night," said BP spokesman Jan-Erik Geirmo. "It will still take some days until we have normal production level," he added.

Valhall produces around 50,000-60,000 barrels of oil a day and 0.54 billion cubic meters of gas a year.

Valhall was forced to close April 2 for checks and maintenance after BP found some corrosion in its produced water system. The company has carried out a series of ultrasonic and radiographic inspections and carried out repairs using biocides to remove the bacteria.

BP Norway's chief executive, Trevor Garlick, called the outage "disappointing" in an interview with Dow Jones Newswires earlier in June.

Valhall is in the southern part of the North Sea and is routed via a pipeline to the Ekofisk field from where it is piped to Teesside in northeast England. The field is currently being redeveloped to ensure it can produce for another 40 years. A new field center is being built there, due to be operational in 2011.

BP, which operates Valhall, has a 28.09% stake in the field, as do Enterprise Oil Norge and Hess Norge. Total SA (TOT) has a 15.72% stake.

Company Web site: www.bp.com

-By Elizabeth Adams, Dow Jones Newswires; [phone]; [e-mail]