Concerns about a looming default by Greece weighed the markets down to a lower open with the Dow falling 56 points to 12,806. Nasdaq dropped 14 points to 2890.

On the upside

Title insurer Fidelity National will acquire casual dining chain operator O'Charley's (Nasdaq: CHUX) in a deal valued at approximately $221 million.

Shares of Threshold Pharmaceuticals (Nasdaq: THLD) continued rising after announcing a partnership with Merck on Friday to co-develop and commercialize its cancer treatment TH-302.

BioLineRx (Nasdaq: BLRX) signed an exclusive license agreement with Genoscience and RFS Pharma to develop and commercialize its hepatitis C treatment BL-8030.

On the downside

Fourth quarter earnings for Sohu.com (Nasdaq: SOHU) beat analyst expectations but the company forecast current quarter results well below estimates.

Maxim Group downgraded Renren (NYSE: RENN) to a Sell rating on Friday.

Humana (NYSE: HUM) reported higher fourth quarter earnings but the company forecast 2012 results below analyst expectations.

In the broad market, declining issues outpaced advancers by a margin of 2 to 1 on the NYSE and by more than 5 to 3 on Nasdaq. The Russell 2000 which tracks small cap stocks lost 3 points to 828.