(June 2): U.S. stocks opened lower on Tuesday lower amid uncertainty over the outcome of Greece's negotiations with creditors and ahead of data that could point to the timing of a U.S. rate hike.

Data due on Tuesday includes April factory orders at 10:00 a.m. ET (1400 GMT). Demand for manufactured goods is likely to have been flat after a strong showing in March.

The auto industry will report sales for May and analysts expect demand to have been flat or down slightly from last year.

"If the Fed keeps delaying and doesn't start the process of a rate hike, they are going to lose credibility," said Rick Meckler, president of LibertyView Capital Management in Jersey City, New Jersey, which oversees about $1 billion.

Meckler reckons that September is the best bet for a hike.

Investors also keep an eye on Greece, which must repay four loans totaling 1.6 billion euros ($1.8 billion) to the International Monetary Fund this month, starting with a 300 million euro payment on June 5.

The leaders of Germany, France and Greece's international creditors agreed late on Monday to work with "real intensity" as they try to reach a deal that would prevent a default.

The dollar hit a 12 1/2-year high against the yen in Asian trade, before pulling back to trade down against the Japanese currency and the euro.

"Stocks have been trying to break out of the narrow trading range but Greece has kept a cap on that," said Meckler.

At 9:44 a.m. ET (1344 GMT) the Dow Jones industrial average was down 85.18 points, or 0.47 percent, at 17,955.19, the S&P 500 was down 10.01 points, or 0.47 percent, at 2,101.72 and the Nasdaq Composite was down 27.14 points, or 0.53 percent, at 5,055.79.

All the 10 major S&P 500 indexes were lower with the utilities index falling the most with a 1.33 percent drop.

Airline stocks were hit by media reports of a bomb threat on a U.S. Airways flight. A few reports said the threat was a hoax.

Dollar General rose 2.7 percent to $74.80 after the discount retailer's quarterly same-store sales beat analysts' expectations.

Cracker Barrel rose 3 percent to $144.11 after the restaurant and gift store operator's results beat estimates.

Zions Bancorp fell 5.9 percent to $30.28 after the Gulf Coast-focused bank announced a restructuring.

PVH Corp rose 5.8 percent to $110.80 after the apparel maker reported better-than-expected quarterly results and raised its full-year profit forecast.

Declining issues outnumbered advancers on the NYSE by 1,873 to 877, for a 2.14-to-1 ratio on the downside. On the Nasdaq, 1,503 issues fell and 757 advanced for a 1.99-to-1 ratio favoring decliners.

The S&P 500 index showed no new 52-week highs and one new lows, while the Nasdaq recorded 15 new highs and 20 new lows.