(Reuters) - Stock futures fell on Monday as investors returned to the market after a holiday-shortened trading week, focused on the meeting of euro zone finance ministers on Greece and negotiations in the U.S. over the "fiscal cliff."

 Euro zone finance ministers and the International Monetary Fund will seek to unfreeze the second bailout package for Greece on Monday, but they first need to agree if some of the official loans to Athens might eventually be forgiven to cut Greek debt.

 U.S. lawmakers have made little progress in the past 10 days toward a compromise to avoid the harsh tax increases and government spending cuts scheduled for Jan. 1, a senior Democratic senator said on Sunday.

 Knight Capital Group Inc. (NYSE: KCG) is in talks about possibly selling its market-making operation, its largest and most profitable business, but it is not known if a deal will happen, a source said on Saturday.

 Apple Inc. (Nasdaq: AAPL) has asked a federal court to add six more products to its patent infringement lawsuit against Samsung Electronics Co. (005930.KS), including the Samsung Galaxy Note II, in the latest in move in an ongoing legal war between the two companies.

 U.S. shoppers went to stores earlier this Thanksgiving weekend and bought online more than in years past, giving retailers a strong start to the holiday shopping season, data showed on Sunday.