Stock fell on Monday after a five-week rally on concerns Greece may be unable to avoid a chaotic default as it struggles to reach terms on a new bailout package.

Athens allowed another deadline to slip as political leaders failed to respond to terms for a new bailout from the European Union and Internation Monetary Fund. Greece needs the funds by March to meet big debt repayments.

German Chancellor Angela Merkel stepped up pressure on Greece, warning that time was running short for a deal to be struck.

It's inevitable the risk profile that Greece represents is definitely going to cool the market tone, there is absolutely no way around that, said Peter Kenny, managing director at Knight Capital in Jersey City, New Jersey.

That lack of clarity, the protracted nature of this crisis and the fact that it simply will not go away, it's a bit unnerving to people who have seen the market tack on some very nice early year gains, and it forces people to want to be a little cautious.

The Dow Jones industrial average <.DJI> was down 39.01 points, or 0.30 percent, at 12,823.22. The Standard & Poor's 500 Index <.SPX> was down 3.86 points, or 0.29 percent, at 1,341.04. The Nasdaq Composite Index <.IXIC> was down 7.66 points, or 0.26 percent, at 2,898.00.

The S&P has rallied for five straight weeks on better-than-expected U.S. economic data, punctuated by Friday's solid employment report, pushing the index up nearly 7 percent for the year.

Hasbro Inc fell 0.3 percent to $35.76 after the maker of Nerf foam toys and Monopoly board games reported a fourth-quarter profit just above analysts' lowered expectations.

Humana Inc posted a big rise in fourth-quarter profit, but revenues came in below Wall Street expectations. Its shares fell 4.6 percent to $86.03. The Morgan Stanley healthcare payor index <.HMO> lost 0.7 percent.

Through Monday morning, of the 290 companies in the S&P 500 reporting results, 60 percent posted earnings that topped Wall Street expectations, tracking below recent quarters at this point of the reporting season.

Other companies expected to post earnings include Yum Brands Inc , Pioneer Natural Resources Co
, Dun and Bradstreet Corp and Anadarko Petroleum Corp .

Fidelity National Financial Inc agreed to buy O'Charley's Inc for $9.85 a share in a deal that values the casual dining chain at $221 million in cash. O'Charley's shares surged 42.2 percent to $9.84.

Semiconductor stocks lost ground, dragged lower by a drop in Micron Technology Inc in the first trading session after the death of its chief executive. Micron shares were off 3 percent to $7.71, while the PHLX semiconductor index <.SOX> dropped 1.3 percent.

(Reporting By Chuck Mikolajczak; editing by Jeffrey Benkoe)