* Decline in oil prices weighs on energy shares
* Priceline rallies after results, Wal-Mart down
* Dow down 0.24 pct, S&P down 0.11 pct, Nasdaq up 0.37 pct (Updates to afternoon trading)
By Caroline Valetkevitch
NEW YORK, Feb 19 (Reuters) - The Dow and S&P 500 eased on Thursday following declines in energy shares and a disappointing outlook from Wal-Mart, while the Nasdaq hit another 15-year high as Priceline shares jumped.
Uncertainty over prospects of a debt deal with Greece added to investor caution. Germany rejected a Greek proposal for a six-month extension to its euro zone loan agreement, saying it fell short of conditions set out by the country's euro zone partners.
A drop in shares of Wal-Mart Stores Inc weighed down the Dow after the company cut its sales outlook, citing the stronger dollar. Shares dropped 3.2 percent to $83.52. Wal-Mart also said it would raise entry-level wages to $9 an hour.
Boosting the Nasdaq, which rose for a seventh straight session, Priceline Group shares rallied 8.5 percent to $1,218.05 on its results. The stock also was the S&P 500's largest daily percentage gainer.
The S&P energy index fell 0.8 percent while shares of Exxon Mobil dropped 1.7 percent to $89.44 as oil prices slid a second day following another big weekly build in U.S. crude inventories.
The decline in energy prices has eroded the profits of oil companies, and many have cut 2015 spending plans. But S&P 500 fourth-quarter earnings overall have been better than expected.
"I think it's likely to stay strong. The rally is broadening out, and many more sectors are being included now as strong performers," said Bruce Zaro, chief technical strategist at Bolton Global Asset Management in Boston.
The Dow Jones industrial average fell 44.08 points, or 0.24 percent, to 17,985.77, the S&P 500 lost 2.23 points, or 0.11 percent, to 2,097.45 and the Nasdaq Composite added 18.34 points, or 0.37 percent, to 4,924.70.
For the whole S&P 500, earnings for the quarter are up 6.5 percent from a year ago, above a Jan. 1 estimate for 4.2 percent growth, Thomson Reuters data showed. The S&P 500 index is up 1.9 percent since the start of the year.
S&P utilities, down 1.1 percent, had the biggest decline among sectors, with shares of Scana falling 1.9 percent to $58.27 following its results.
The biggest percentage decliner in the S&P 500 was Host Hotels & Resorts, down 7.1 percent at $21.87, after a disappointing forecast.
About 6 billion shares changed hands on U.S. exchanges, below the 7.1 billion average for the month to date, according to BATS Global Markets.
NYSE declining issues outnumbered advancing ones 1,581 to 1,452, for a 1.09-to-1 ratio; on the Nasdaq, 1,440 issues rose and 1,256 fell, a 1.15-to-1 ratio favoring advancers.
The S&P 500 posted 66 new 52-week highs and one new lows; the Nasdaq Composite recorded 104 new highs and 22 new lows. (Editing by Bernadette Baum and Nick Zieminski)