* FTSEurofirst 300 up 0.5 pct, hits 7-year high
* Lafarge, Holcim drop as conflict over merger terms deepens
* Stronger dollar seen halting U.S. earnings growth in 2015
By Blaise Robinson
PARIS, March 16 (Reuters) - European stocks rose on Monday, shrugging off losses on Wall Street and extending their recent sharp rally, as investors bet that a renewed drop in the euro would boost the region's economy and lift exporter earnings.
Shares in Lafarge fell 4.2 percent and Holcim dipped 1.4 percent as an argument deepened between the two cement majors over the terms of their planned merger.
"We expect this very public showing of disunity will be seen as raising the likelihood of a break-up in the deal, although we believe that an agreement will ultimately be reached," Bernstein analysts wrote in a note.
Shares in Irish peer CRH - which has agreed to buy assets from Lafarge and Holcim as they seek to win regulatory approval for their planned merger - were down 2.9 percent.
At 0837 GMT, the FTSEurofirst 300 index of top European shares was up 0.5 percent at 1,586.06 points, a fresh seven-year high.
The euro fell as low as $1.0457 early in Asia on Monday, its lowest since January 2003, after a brief bounce above $1.0600 overnight. The single currency sank last week against the dollar as the European Central Bank began asset purchases that will eventually help pump a trillion euros into the economy.
The relentless slide in the euro over the past year has given a significant lift to European corporate results after years of stagnating profits. The drop in the single currency is seen translating into a 10 to 13 percent lift in earnings in 2015. For U.S. companies, however, the stronger dollar is set to hit results.
"While the lower euro helps boost European stocks, it really is the strong dollar that has been sending U.S. shares lower. We could soon see analysts starting to forecast negative U.S. earnings growth for 2015," said Mirabaud Securities senior equity sales trader John Plassard in Geneva.
Around Europe, UK's FTSE 100 index was up 0.3 percent, Germany's DAX index up 0.8 percent, trading at a record high, and France's CAC 40 up 0.5 percent.
Shares in Actelion gained 1 percent after the Swiss biopharmaceutical firm announced positive results from its latest heart-drug trials.
Energy shares dipped, with Total down 0.2 percent and Eni down 1.5 percent, as oil prices tumbled. U.S. crude dropping more than 2 percent at one point to a six-year low amid oversupply fears. The International Energy Agency said on Friday that the global supply glut is growing and U.S. production shows no sign of slowing.
Investors' main focus this week will be the U.S. Federal Reserve's two-day meeting beginning on Tuesday. After successive months of strong jobs data, expectations have been growing that the Fed will point towards a June rate rise by dropping a pledge to be "patient" in considering such a move.
Europe bourses in 2015: link.reuters.com/pap87v
Asset performance in 2015: link.reuters.com/gap87v
Today's European research round-up (Additional reporting by Alistair Smout in London; Editing by Hugh Lawson)