* FTSEurofirst 300 up 0.3 pct

* Telenor, TeliaSonera rally after unit merger deal

* Metro, Adidas sink on worries over exposure to rouble

By Blaise Robinson

PARIS, Dec 3 (Reuters) - European stocks rose in early trading on Wednesday, with Nordic telecom operators Telenor and TeliaSonera rallying after agreeing to merge their Danish operations.

Shares in both firms gained 1.7 percent after unveiling their join-venture deal. The companies hope to save 800 million Danish crowns ($133 million) annually in efficiency gains.

Shares in Germany's sportswear firm Adidas AG and food retailer Metro featured among the top losers, hurt by worries over the two companies' exposure to Russia's troubled economy.

Metro was down 5.8 percent after JPMorgan downgraded the stock to 'underweight' from 'neutral', citing Russia.

"We are increasingly concerned about sales in local currency and margins in Russia, in addition to the very significant currency headwind," the analysts wrote in a note.

Adidas was down 2.7 percent after Barclays analysts downgraded the stock to 'equal weight' from 'overweight', citing worries over its high exposure to the rouble.

At 0916 GMT, the FTSEurofirst 300 index of top European shares was up 0.3 percent at 1,396.37 points. The index has strongly rebounded from a low hit in mid-October, but the rally has lost steam in the past week.

"Indexes remain in a trading range started in late November. The bias remains bullish, but there isn't a strong catalyst to help fuel the rally at the moment. This could change with the ECB tomorrow and Friday's U.S. payroll figures," Saxo Bank trader Andrea Tueni said.

"Draghi would please investors with some sort of timetable for quantitative easing, but even if he just repeats the ECB's strong commitment to act, it could be enough to spark a Santa Claus rally."

According to euro money market traders polled by Reuters, the European Central Bank probably won't announce more stimulus measures at Thursday's monetary policy meeting.

However, momentum is building for the ECB to launch a programme of sovereign-bond buying to revive the euro zone economy, with most signs pointing to March for a decision.

Data showed on Wednesday Markit's final November Composite Purchasing Managers' Index (PMI), based on surveys of thousands of companies across the region and seen as a good indicator of growth, had fallen to 51.1 from October's 52.1, missing an earlier flash reading of 51.4.

Europe bourses in 2014: http://link.reuters.com/pap87v

Asset performance in 2014: http://link.reuters.com/gap87v

Today's European research round-up

(Editing by Gareth Jones)