NEW YORK (Reuters) - Hellman & Friedman LLC and Bain Capital LLC are among a handful of parties that have made offers for software maker Deltek Inc (>> Deltek Inc.), as bidders move into a second stage of due diligence, two sources close to the matter said.

Deltek has not yet set a deadline for second-round bids, although this could come in the next two weeks, said one of the sources. The auction is being run by Greenhill & Co Inc (>> Greenhill & Co., Inc.) and Credit Suisse Group AG (>> Credit Suisse Group AG), according to the sources.

Deltek, which has a market capitalization of about $900 million, did not immediately respond to a request for comment while Hellman & Friedman, Bain, Greenhill and Credit Suisse declined to comment.

The sale of Herndon, Virginia-based Deltek, which provides enterprise software for government contractors, comes as the company returns to profitability after a lackluster 2011. Last week it reported second-quarter operating income of $8.8 million, up from an operating loss of $1.9 million last year.

Credit Suisse led Deltek's second initial public offering in 2007 after an extensive recapitalization. The company, founded in 1983, first began trading publicly in 1997 and was taken private in 2002.

New Mountain Capital LLC, the company's majority owner, also owns Apptis Inc and other federal IT services companies. It initially acquired a 75 percent stake in Deltek in April 2005. The buyout firm currently holds a 59.2 percent stake.

Shares of Deltek ended trading at $13.51 on Tuesday after rising as much as 4 percent on the news. They are up 34 percent year-to-date, outperforming the S&P Application Software Sub-Industry Index <.GSPCMSF> by 13 percentage points on expectations that the company may sell itself.

Concerns over a slowdown in government spending, which could have an impact on the outlook for Deltek's business, may weigh on the deal. However, Deltek said in its earnings statement last week it expected strong growth through the rest of the year.

(Editing by Steve Orlofsky)

By Nadia Damouni and Greg Roumeliotis

Stocks treated in this article : Credit Suisse Group AG, Greenhill & Co., Inc., Deltek Inc.