Private equity firm New Mountain Capital LLC is exploring a sale of Inmar Inc, a provider of coupon processing and logistics services to companies, seeking more than $600 million, according to three people familiar with the matter.

An auction for Winston-Salem, North Carolina-based Inmar is being handled by Morgan Stanley and Wells Fargo & Co, the people said this week on condition of anonymity because the process is confidential.

Inmar's earnings before interest, tax, depreciation and amortization are seen at between $60 million and $70 million and New Mountain is looking for more than 10 times that amount, the people said.They cautioned that New Mountain may decide not to sell due to a gap in valuation expectations with other private equity firms which have expressed an interest in Inmar.

An Inmar spokeswoman declined to comment. Representatives for New Mountain, Morgan Stanley and Wells Fargo did not respond to requests for comment.

Founded in 1980, Inmar runs electronic commerce networks that allow retailers, manufacturers and their trading partners to manage their supply chain and process transactions, including consumers cashing in on their coupons.

New Mountain acquired a majority stake in Inmar in 2007 in a $350 million deal. The New York-based private equity firm committed about $200 million as equity, according to a press article on its website citing Doug Londal, who is now New Mountain's president.

Inmar managed 3.5 billion commerce transactions last year and since its acquisition by New Mountain in 2007 it has created 859 new jobs, increasing its workforce by 24 percent, the Private Equity Growth Capital Council, which represents the interests of the private equity industry, said in April.