MGM sends out books, process going slow--sources

NEW YORK Dec 17 (Reuters) - First-round bids for Metro-Goldwyn-Mayer will come in later than initially expected as negotiations over confidentiality agreements have slowed the sale process, sources familiar with the matter said on Thursday.

MGM, the famed film studio that said in November it was exploring a potential sale of itself, has sent out a sales prospectus to all the parties who signed its non-disclosure agreement, including Time Warner Inc (TWX.N) and Lions Gate Entertainment (LGF.N), the sources said.

But getting potential bidders to sign the NDAs has taken a while because MGM, which is owned by a group of private equity and media companies, wanted to restrict the ability of buyers to talk directly to MGM's creditors, one of the sources said.

MGM has not set a deadline for the first round of bids yet, even though potential bidders had expected to put in offers before Christmas, the sources said.

MGM, which is owned by a group including private equity firms Providence Equity Partners and TPG [TPG.UL], and media companies Sony Corp (6758.T) and Comcast Corp (CMCSA.O), is struggling with nearly $4 billion in debt. (Reporting by Anupreeta Das and Jui Chakravorty; Editing by Gary Hill)