* Will be first main market London IPO of 2012
* Oil explorer to be first Russian IPO since last July
* Deal will value RusPetro at $676 mln
* Amount raised is bottom of $250-$350 mln range
By Megan Davies
MOSCOW, Jan 18 (Reuters) - Oil producer RusPetro will bank $250 million from its London listing, the company said, defying choppy market conditions that have put paid to sizeable flotations in Europe since the summer.
Deepening concern over the euro zone debt crisis in the past six months has sent investors running for cover and forced most companies to put on ice their plans for initial public offerings (IPOs) -- considered the riskier end of the share sale spectrum.
Ruspetro, which will be London's first main market IPO since Ophir Energy last July, spent December and January canvassing investor interest before launching a one-day bookbuild on Tuesday.
Conditional trading of the shares is due to begin on Thursday and unconditional trading on January 24. The UK-based company, which has its main assets in western Siberia, will be listed under the ticker.
RusPetro, which had hoped to raise $250-$350 million from the IPO according to a presentation document seen by Reuters, said it priced the offer at 134 pence, confirming figures reported earlier by Reuters.
It had already lined up enough indicative orders to cover the book at this price before launching the offer, a source close to the deal said.
The IPO values the company at $676 million and the free float after the IPO is expected to be 40 percent.
"This shows there is still an appetite for issues if the valuation is low enough, or if the opportunity is unique or specialist," said Chris Weafer, chief Russia strategist at investment bank Troika Dialog.
Troika estimates $50 billion of potential Russian IPOs are waiting on the sidelines for conditions to improve. Private Russian companies raised $4.5 billion in IPOs last year, mostly in London, and $5.5 billion the year before.
"Market conditions for big IPOs remain very difficult. They will still have to wait until the second half of 2012 or accept a low valuation," Weafer added.
The float will be the first by a Russian company since fertiliser producer Phosagro raised $538 million in London in July, shortly before a U.S. sovereign rating downgrade and the escalating euro zone crisis sparked a global equities sell-off.
Faced with unpredictable markets, those involved in running IPOs have been looking at ways to reduce a company's exposure to a change in market sentiment during the offer period.
RusPetro's unusually structured IPO -- a one-day bookbuild after weeks of informal investor meetings, rather than the usual two-week roadshow followed by two-week bookbuild -- could be looked at by others seeking to smooth their ride to market.
RusPetro will use the proceeds of the float to develop existing operations and pay down pre-IPO debt of $444 million, according to the presentation seen by Reuters.
The company is 29 percent owned by management including Executive Director Alexander Chistyakov, a former director of several state utility firms.
Some 48 percent is controlled by a vehicle called Limolines -- itself 50 percent owned by Andrey Likhachev, chairman of tycoon Oleg Deripaska's power unit EuroSibEnergo, and 50 percent by investment fund Altera Capital.
Altera is run by Kirill Androsov, a former deputy economy minister who went on to serve as deputy chief of staff to Prime Minister Vladimir Putin from 2008-2010.
RusPetro Chief Executive Donald Wolcott is a former director of Yukos, once Russia's largest oil company, which was forced into bankruptcy by back-tax claims and whose assets were largely nationalised.
Bank of America Merrill Lynch is sole global co-ordinator on the offering, with Mirabaud Securities and Renaissance Capital acting as bookrunners.