(Adds detail, quote, share price)
* Q1 net profit down 14 pct y/y due to exchange rate
* Free cash flow more than tripled to 121 bln rbls
* Rosneft says Arctic development plan on track
By Vladimir Soldatkin
MOSCOW, April 30 (Reuters) - Rosneft, Russia's No. 1 oil company, said on Wednesday its first-quarter core profit more than doubled, year-on-year, to 289 billion roubles ($8 billion), beating analyst forecasts, on the back of rising sales.
Analysts, polled by Reuters, had expected January-March earnings before interest, taxation, depreciation and amortisation (EBITDA) of 280.7 billion roubles.
The company became the world's largest listed oil producer last year, when it bought the Anglo-Russian TNK-BP oil firm for $55 billion in what some observers see as Russian President Vladimir Putin's strategy of pursuing state capitalism.
After the deal, BP ended up with a 19.75 percent stake in the Kremlin energy champion. Rosneft, headed by Igor Sechin, a long-standing ally of Putin, borrowed more than $30 billion from banks to finance the TNK-BP purchase.
The company said on Wednesday its free cash flow more than tripled to reach 121 billion roubles in January-March, while net debt declined by 11.5 percent to 1.59 trillion roubles.
Rosneft's first-quarter net income declined by 14 percent to 88 billion roubles due to the impact of a weakening rouble, which it put at 84 billion roubles.
The Russian currency is down some 10 percent against the dollar so far this year.
Banking sources said on Tuesday that U.S. sanctions imposed on Sechin earlier this week over the Ukraine crisis are threatening Rosneft's plans to raise around $4 billion of oil prepayment loans.
Markets have largely brushed off the sanctions.
Rosneft's share prices reversed losses after the company published its results and were up 0.1 percent in late trade, in line with the broader market.
Putin said on Tuesday that Moscow saw no need for counter-sanctions against the West but that it could review its contracts with international majors if sanctions continued. Rosneft has deals with Exxon Mobil, Eni and Statoil to tap offshore Arctic resources.
Rosneft aims to drill a first exploratory well in the Arctic Kara Sea, which it plans to develop with Exxon, in August.
"Preparation for drilling the first well in the Kara Sea is unquestionably one of our key projects. Monetisation of Russia's enormous resource potential in the offshore Arctic is the key priority for the company," Sechin said in a statement.
($1 = 35.6277 Russian Roubles) (Reporting by Vladimir Soldatkin, editing by Nigel Stephenson)