* Ceasefire deal reached between Ukraine, Russia
* Sweden introduces negative interest rates, bond buys
* Cisco up after results; Tesla falls
* Expedia to buy Orbitz; shares jump
* Indexes up: Dow 0.24 pct, S&P 0.55 pct, Nasdaq 0.68 pct (Updates to late morning)
By Chuck Mikolajczak
NEW YORK, Feb 12 (Reuters) - U.S. stocks climbed on Thursday and the Nasdaq touched a 15-year high following a ceasefire agreement between Russia and Ukraine and surprising stimulus measures by Sweden's central bank, although soft economic data tempered gains.
Leaders of Germany, France, Russia and Ukraine agreed a deal to end fighting in eastern Ukraine, potentially removing a concern for investors, although the pact remained fragile.
Talks over Greek debt with euro zone finance ministers failed to yield an agreement on Wednesday, although negotiations were set to continue next week. Greek Prime Minister Alexis Tsipras was in Brussels to state his case for more financial help to fellow EU leaders after the talks with finance ministers stalled.
With talks ongoing, the European Central Bank further raised the cap on emergency funding for Greek banks by about 5 billion euros to 65 billion euros, Greek central bank and government officials told Reuters.
"Whether it is Greece or Ukraine, the market is giving the policy makers the benefit of the doubt that some of these talks will materialize in real progress," said Anastasia Amoroso, global market strategist at J.P. Morgan Funds in New York.
Also providing a lift was a decision by Sweden's Riksbank to introduce negative interest rates and launch bond purchases, while saying it could take further steps to fight falling prices.
"It's definitely a positive, the fight against deflation or the fight against falling inflation has to come with some sort of tools and that is part of the toolkit that central banks have to engage," said Amoroso.
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.
The Dow Jones industrial average rose 42.2 points, or 0.24 percent, to 17,904.34, the S&P 500 gained 11.34 points, or 0.55 percent, to 2,079.87 and the Nasdaq Composite added 32.85 points, or 0.68 percent, to 4,834.03.
The Nasdaq touched a peak of 4,840.15, its highest level since March 2000, while the S&P 500 was about 0.5 percent from its intraday record set on Dec. 29.
Cisco Systems jumped 8.1 percent to $29.11 after the network equipment maker reported stronger-than-expected quarterly revenue and profit.
Tesla Motors dropped 7 percent to $197.94 after it missed fourth-quarter sales targets and analysts' profit expectations.
Orbitz Worldwide shares surged 21 percent to $11.64 after the online travel agency agreed to be acquired by Expedia for about $1.38 billion. Shares of Expedia were up 15.9 percent at $90.63.
American Express shares dropped 6.1 percent to $80.74 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 2,303 to 621, for a 3.71-to-1 ratio on the upside; on the Nasdaq, 1,767 issues rose and 798 fell for a 2.21-to-1 ratio favoring advancers.
The benchmark S&P 500 index was posting 49 new 52-week highs and no new lows; the Nasdaq Composite was recording 89 new highs and 13 new lows.
Editing by Bernadette Baum