* FTSEurofirst 300 up 0.4 pct, Euro STOXX 50 up 0.7 pct
* AstraZeneca rallies 15 pct as Pfizer says to buy firm
* Bayer jumps after posting forecast-beating results
* Only 50 pct of Europe firms meet/beat forecasts so far
By Blaise Robinson
PARIS, April 28 (Reuters) - European stocks rose on Monday as merger and acquisition moves in the pharmaceuticals sector and forecast-beating results from Germany's Bayer outweighed the impact of tensions in Ukraine.
Shares in AstraZeneca rallied 15 percent after U.S. rival Pfizer said it wanted to buy the British drugmaker in a deal potentially worth more than $100 billion. The sharp jump in the stock increased the group's market capitalisation by roughly 7.7 billion pounds, or $13 billion.
"Thanks to central banks' massive (provision of) liquidity, a lot of companies are now looking for takeover targets across the board, which is very positive for the market," said Lionel Jardin, head of institutional sales at Assya Capital in Paris.
"It helps forget about Ukraine, which seems to be slowly disappearing from investors' radar screens despite the violence. With time, investors are getting used to the crisis."
Shares in German conglomerate Siemens dropped 2.3 percent after the group said it was mulling an asset swap with France's Alstom, which has received an offer for its power arm from U.S. bellwether General Electric.
Alstom shares were still suspended on Monday while shares in Bouygues, which has a 29 percent stake in Alstom, were up 2.8 percent in brisk volumes.
At 1023 GMT, the pan-European FTSEurofirst 300 index , which hit a near six-year high earlier this month, was up 0.4 percent at 1,338.36 points.
The index lost 0.8 percent on Friday as investors moved to the sidelines, wary of a potential deterioration in the Ukrainian crisis over the weekend.
U.S President Barack Obama announced new sanctions against some Russians on Monday to stop President Vladimir Putin from fomenting the rebellion in eastern Ukraine, as pro-Moscow rebels showed no sign of curbing their uprising, seizing public buildings in another town in the east.
On the earnings front, shares in Bayer jumped 4.7 percent after posting forecast-beating quarterly results.
Despite Bayer, the overall earnings picture for Europe remains mixed. About one-fifth of companies of the STOXX Europe 600 index have reported quarterly results so far, of which only half have beaten or met analysts' expectations. In comparison, some 75 percent of U.S. companies have beaten or met forecasts this earnings season.
Around Europe, UK's FTSE 100 index was up 0.3 percent, Germany's DAX index up 0.7 percent, and France's CAC 40 up 0.4 percent. The euro zone's blue-chip Euro STOXX 50 index was up 0.7 percent at 3,167.73 points.
"Markets are on the rise with all the M&A activity, but gains should be capped ahead of the string of macro data and central bank signals expected later this week," FXCM analyst Vincent Ganne said.
"This week, we get the all-important euro zone inflation data, as well as the Fed's policy meeting, which should provide insight on the pace of tapering."
U.S. Federal Reserve policymakers are set to meet on Tuesday and Wednesday.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Additional reporting by Atul Prakash in London; Editing by Susan Fenton)