(Updates with quotes, details, share prices)
By Marja Novak
LJUBLJANA, May 14 (Reuters) - Slovenia's Krka posted a 29.5 percent rise in first-quarter net profit to 55.1 million euros helped by financial gains from a strengthening of the Russian rouble between January and March, the drugs maker said on Thursday.
"The rouble's appreciation relative to its 2014 year-end value resulted in net foreign exchange gains which increased financial income," said Krka, which is Slovenia's largest listed company.
The average value of the rouble versus the euro remained more than 30 percent weaker than a year earlier, however, hurting revenue which fell to 289.3 million euros from 298 million a year earlier.
Sales in the Russian Federation, which is Krka's largest market "rose by 1 percent in roubles but fell by 27 percent when expressed in euros," it said.
The company held to a 2015 forecast made in November which called for net profit in line with 2014's 166.2 million euros and sales of about 1.3 billion euros versus 1.2 billion last year.
Krka shares closed 0.36 percent higher at 67.84 euros on Thursday versus the blue-chip SBI index which gained 0.95 percent. (Reporting by Marja Novak; editing by Pravin Char and Jason Neely)