BUDAPEST, April 14 (Reuters) - Hungary's biggest lender OTP is in talks to buy Slovenian bank Nova KBM from private equity group Apollo in a deal worth roughly 1 billion euros ($1.2 billion), people close to the matter said.

OTP has sought to expand its footprint in the Balkans in recent years. It has bought large banks in Croatia, Serbia and several other countries. It owns a small bank in Slovenia, and the purchase of Nova KBM could make it the country's number one.

Apollo, which owns 80% in Nova KBM, and OTP were not immediately available for comment. The European Bank for Reconstruction and Development, which owns 20%, declined to comment.

($1 = 0.8356 euros) (Additional reporting by Karin Strohecker. Editing by Mark Potter)