* US GDP grows a lower-than-expected 1.9 pct in Q2

* Weakly jobless claims jump, suggesting weak labor market

* Shares of Starbucks, Motorola rise after results

* Exxon Mobil shares fall after earnings miss expectations

By Walter Brandimarte

NEW YORK, July 31 (Reuters) - U.S. stock index futures pointed to a sharply lower open on Thursday after data showed the U.S. economy grew less than expected in the second quarterand weekly jobless claims surged, reviving recession fears.

The economic data offset positive quarterly results from Motorola Inc (MOT.N: Quote, Profile, Research), as well as news that Starbucks Corp (SBUX.O: Quote, Profile, Research) had stuck by its 2009 profit target despite posting its first quarterly loss as a public company.

U.S. gross domestic product, or GDP, grew at a 1.9 percent annual rate, below analysts' forecast in a Reuters poll for a 2.0 percent rise. The number of U.S. workers filing new claims for jobless benefits jumped 44,000 last week, above the Wall Street consensus.

"At first glance, the 1.9 percent on GDP is OK, even though it might be slightly below consensus. What the data tells us is that stock market volatility will continue," said Subodh Kumar, chief investment strategist at Subodh Jumar & Associates in Toronto.