Northgate Public Services (NPS), whose clients include Britain's police, local government agencies and the National Health Service, was put up for sale earlier this year.

Rothschild [ROT.UL] was appointed to run the process, which could fetch about $600 million.

NPS is attracting interest from a number of potential buyers and first round bids in an auction process are due next week, the banking sources said.

KKR declined to comment.

A debt financing of about 300 million pounds equates to approximately 5.5-6.5 times NPS' earnings before interest, tax, depreciation and amortisation (EBITDA) of some 45 million pounds, including undrawn debt, the banking sources said.

Debt is likely to be in the form of an all-senior leveraged loan package, or senior leveraged loans and second lien loans, the bankers said.

NPS is the smaller of two divisions within Northgate Information Solutions. The other is NGA Human Resources (formerly known as NorthgateArinso) which focuses on human resources software for clients across Europe, the United States and Asia.

(1 US dollar = 0.6228 British pound)

(Editing by David Clarke)

By Claire Ruckin