Contractor to tell SFO about its own misconduct in Nigeria in deal to receive lenient treatment

Contractor MW Kellogg plans to report its own corruption offences to the Serious Fraud Office, it has emerged.

The SFO has been investigating the UK contractor, which is partly owned by US engineer KBR, for more than three years.

Kellogg will tell the SFO about misconduct in Nigeria during the construction of the Bonny Island natural gas plant in the Niger delta. According to a Financial Times report, Kellogg will admit to the offences in a deal designed to secure more lenient treatment.

The SFO is investigating corruption among UK construction companies, particularly in their international operations, and is encouraging companies to admit to breaches in return for more lenient treatment.

Its cases in the past 12 months include bridge-building firm Mabey & Johnson, which revealed in July 2009 that it would plead guilty to charges of corruption related to activities in Jamaica and Ghana in 1993 and 2001. The £55m-turnover firm was fined £6.6m as a result.

Amec and Balfour Beatty have also been fined, although the SFO deemed both firm's activities to be insufficiently serious to warrant prosecution, so both cases were settled on a civil basis.

Last year KBR and Halliburton, then a co-owner of Kellogg, paid a $579m (£378m) fine in the US for using a $130m fund to bribe Nigerian officials to win more than $5bn of construction work at Bonny Island. The fine was the biggest ever imposed on US companies for bribery.

KBR admitted using Kellogg as a conduit in an "intentional effort" to "insulate itself" from US laws against bribing foreign public officials, say US government case documents, the FT reported.