* Ceasefire deal reached between Ukraine, Russia
* Cisco shares rally after results; Tesla falls
* TripAdvisor soars on results; Expedia to buy Orbitz
* Indexes up: Dow 0.5 pct, S&P 0.8 pct, Nasdaq 0.9 pct (Updates to afternoon trading)
By Ryan Vlastelica
NEW YORK, Feb 12 (Reuters) - U.S. stocks advanced broadly on Thursday, with a rally in technology stocks leading the Nasdaq to a 15-year high, helping to offset the impact of some tepid economic data.
Sentiment was also boosted by a ceasefire agreement between Russia and Ukraine, which soothed concerns that tensions in the region would prove a further drag on Europe's economy.
The S&P information technology sector rose 1.4 percent in its third straight daily advance. Cisco Systems climbed 9.4 percent to $29.46 in the network equipment maker's biggest one-day jump since May 2013 after reporting earnings and revenue that beat expectations.
TripAdvisor Inc soared 24 percent to $83.35 a day after posting revenue that topped forecasts. Fellow online travel company Expedia jumped 16 percent to $90.99. Earlier, Expedia agreed to buy Orbitz Worldwide for $1.38 billion in cash.
With 76 percent of the S&P 500 having reported, about 71.4 percent of companies have topped earnings expectations, according to Thomson Reuters data, while 56.8 percent have topped on revenue. That compares to the long-term average of 63 percent for earnings and 61 percent for revenue.
Overseas, leaders of Germany, France, Russia and Ukraine agreed a deal to end fighting in eastern Ukraine, potentially removing a concern for global investors, although the pact remained fragile. The news contributed to oil prices advancing 3.9 percent on the day, which in turn lifted the S&P energy index 0.9 percent.
"There's definitely a feel-good situation leading from the reduction in geopolitical risk, while the rise we're seeing in the energy sector is really helping the overall benchmark," said Michael Mullaney, chief investment officer at Fiduciary Trust Co in Boston.
U.S. economic data was tepid, as initial jobless claims rose more than expected in the latest week, while retail sales barely rebounded in January. In addition, business inventories rose less than expected in December.
At 1:14 p.m. (1815 GMT), the Dow Jones industrial average rose 83.14 points, or 0.47 percent, to 17,945.28, the S&P 500 gained 15.82 points, or 0.76 percent, to 2,084.35 and the Nasdaq Composite added 45.25 points, or 0.94 percent, to 4,846.43.
The Nasdaq touched a peak of 4,847.79, its highest level since March 2000, while the S&P 500 was about 0.4 percent from its intraday record set on Dec. 29.
Tesla Motors dropped 5.6 percent to $200.82 after it missed fourth-quarter sales targets and analysts' profit expectations.
American Express shares dropped 5.9 percent to $80.94 as the biggest drag on the Dow after it said Costco Wholesale would stop accepting its cards in the United States from next April, after a renewal agreement could not be reached. Costco shares edged down 0.2 percent to $147.12.
Advancing issues outnumbered declining ones on the NYSE by 2,321 to 689, for a 3.37-to-1 ratio on the upside; on the Nasdaq, 1,829 issues rose and 815 fell for a 2.24-to-1 ratio favoring advancers.
The benchmark S&P 500 index was posting 63 new 52-week highs and no new lows; the Nasdaq Composite was recording 103 new highs and 14 new lows.
Editing by Bernadette Baum