* Russian oil output in 2010 could fall as much as 4 percent

* LUKOIL Korchagin field seen starting in March 2010

* Monthly production topped 10 mbpd in September

London, Oct 14 (Reuters) - Russian oil output will stagnate in 2010 and begin to decline as mature fields lose production capacity and only one new project comes on line, oil analysts at Bernstein Research said on Wednesday.

Russia, now the world’s largest oil producer, pumped 10.01 million barrels per day last month, up 0.4 percent from the 9.97 million bpd produced in August, both record highs, Russian Energy Ministry data released last week showed. [ID:nL2451607]

But Bernstein analysts said Russian production, which recovered in 2009 after dropping for the first time in a decade in 2008, was merely experiencing a temporary spike following the launches of eight new fields this year.

Senior oil analyst Clint Oswald at Bernstein Research wrote that 0.6 percent year on year growth in the year to the end of September, in a year when eight projects added 640,000 bpd of new production, “does not sound like a great achievement or the start of an up trend.,”

“With only one significant field due to come on stream in 2010 and reduced drilling activity, we continue to expect declining oil output in Russia in the near term,” Oswald wrote in a research note.

He projected three possible scenarios for 2010, assuming decline rates in base production of 3 to 4 percent, resulting in a percentage output drop ranging from 0.29 percent to 1.24 percent down year on year.

LUKOIL LKOH.MM, Russia's second-largest oil producer said in September it expected to start production from one of its Caspian oilfields at Korchagin in March 2010, and to be able to pump 240,000 bpd from two of them by 2016. [ID:nLM221719]

OUTPUT MAY CONTINUE CREEPING HIGHER -BP

Russia has emerged as the world’s oil production leader this year after the Organization of the Petroleum Exporting Countries agreed to cut supply by 4.2 million bpd since September 2008 in a bid to prop up falling oil prices.

OPEC has kept its official output targets unchanged at meetings since, most recently on Sept. 9. Oil prices CLc1 have risen by more than 50 percent this year to around $75 a barrel.

But industry officials said Russia’s September production record was perhaps the end of a strong run.

“We could see Russian production continue creeping up above 10 million bpd, but it will rise at nothing like the rate we saw earlier this century,” BP’s Chief Economist Christof Ruhl told Reuters on Tuesday.

Before this August, Russia’s previous monthly record for oil production was 9.93 million bpd reached in October 2007.

Russian production this year was boosted by the launch of Rosneft's ROSN.MM massive Vankor in the Arctic and several other new fields, including LUKOIL's South Khylchuyu and Verkhnechonskoye fields owned by BP-led TNK-BP TNBPI.RTS. (Additional reporting by David Sheppard in London, editing by Anthony Barker)