By Chuck Mikolajczak

NEW YORK (Reuters) – U.S. stocks slipped on Monday, on the heels of disappointing Chinese economic data and signs of increased tensions surrounding Greek debt negotiations.

China’s exports fell 3.3 percent from a year ago while imports tumbled 19.9 percent, well short of expectations, raising concerns about the world’s second-largest economy.

Greece’s Prime Minister Alexis Tsipras on Sunday ruled out any extension of its international bailout and announced moves to reverse some of the reforms imposed by its lenders. On Monday, European Commission President Jean-Claude Juncker said Greeks should not expect the euro zone to accept the latest terms proposed by Greece.

National Bank of Greece U.S.-listed shares <NBG.N> dropped 7.4 percent to $ 1.12.

“We are seeing heightened nervousness over the Greek elections and the policies that could make or break its EU membership,” said Andre Bakhos, managing director at Janlyn Capital LLC in Bernardsville, New Jersey.

“In addition, the Chinese economic data disappointed and added to the economic global weakness we have been seeing.”

The Dow Jones industrial average <.DJI> fell 60.57 points, or 0.34 percent, to 17,763.72, the S&P 500 <.SPX> lost 4.08 points, or 0.2 percent, to 2,051.39 and the Nasdaq Composite <.IXIC> dropped 11.23 points, or 0.24 percent, to 4,733.17.

U.S. stocks fell on Friday as stronger than anticipated monthly payrolls heightened expectations the U.S. Federal Reserve may hike interest rates by mid-year, but the three major indexes managed to notch gains for the week.

McDonald’s <MCD.N> lost 0.9 percent to $ 93.12. Same-restaurant sales fell a steeper-than-expected 1.8 percent in January.

Achillion Pharmaceuticals <ACHN.O> jumped 15 percent to $ 12.44. Its experimental hepatitis C drug, when used in combination with Gilead Sciences Inc’s <GILD.O> Sovaldi, eradicated signs of the virus after six weeks of therapy. Gilead shares edged up 0.1 percent to $ 97.60.

Qualcomm <QCOM.O> shares gained 3.6 percent to $ 68.71, the biggest boost to the Nasdaq 100 <.NDX>. A source told Reuters the chipmaker is likely to pay China a record fine of around $ 1 billion, ending a 14-month government investigation into anti-competitive practices.

Hasbro <HAS.O> rose 4.7 percent to $ 58.38 after the second-largest U.S. toymaker reported a nearly 31 percent rise in quarterly profit and authorized additional share repurchases of $ 500 million.

Despite some high-profile earnings misses from large multinationals, Thomson Reuters data through Friday show 73 percent of the 322 companies in the S&P 500 that have reported earnings have topped expectations. The beat rate for the past four quarters was 69 percent and fourth-quarter earnings are expected to grow 6.4 percent.

Advancing issues outnumbered declining ones on the NYSE by 1,394 to 1,362, for a 1.02-to-1 ratio; on the Nasdaq, 1,251 issues fell and 1,032 advanced, a 1.21-to-1 ratio favoring decliners.

The benchmark S&P 500 posted 4 new 52-week highs and 2 new lows; the Nasdaq Composite recorded 19 new highs and 9 new lows.

(Editing by Bernadette Baum and Nick Zieminski)