LONDON (Reuters) - Outsourcing group Serco <SRP.L> said it was working with Britain's government to fix any wrongdoing that is discovered from a raft of reviews into its contracts.

Serco, which makes around 45 percent of its revenue from UK public sector work, is facing various government contract reviews and threats of exclusion from future deals after serious faults were found in its delivery of electronic tagging and prisoner escort services.

The group, which runs facilities ranging from Britain's Atomic Weapons Establishment to immigration detention centres in Australia, on Thursday reported adjusted pretax profit was 127.1 million pounds ($197.46 million) in the six months to June 30, up from 114.5 million in 2012.

(Reporting by Neil Maidment; editing by Rhys Jones)