A concerted effort by President Dmitry Medvedev and other top officials to bolster nervy Russian markets failed to impress investors Thursday, despite his pledge that the government would step in with extra funds to plug growing liquidity shortfalls.

"The government and the Central Bank must do everything possible to ensure the flow of additional funds into the financial market,'' Medvedev said during the televised part of a Kremlin meeting attended by senior ministers and state banking officials. "This is absolutely obvious and it must be done."

His comments initially appeared to steady market nerves, but did not produce a hoped-for bounce. After a few hours of flat trading, investors capitulated, and a strong burst of late selling left the MICEX Index down 3.7 percent at 1,073.02 points and the RTS down 2.7 percent at 1,298.08 points at the close.

The RTS has lost 48 percent since its May high, while the MICEX has dropped 45 percent over the same period, as several hundred billion dollars has been wiped off stock values amid falling commodity prices and worries over rising political risk.

Central Bank chairman Sergei Ignatyev conceded Thursday that there was "some [liquidity] shortfall in the banking sector," and said the Central Bank was "taking large-scale steps to refinance several banks.

"Our capabilities fully allow us to increase these operations by several times," Ignatyev said, RIA-Novosti reported.

Ignatyev's comments came after banks borrowed $11.6 billion Thursday in repurchase auctions, and his first deputy, Alexei Ulyukayev, said earlier in the day that the Central Bank could offer as much as 1 trillion rubles ($39 billion) per day in such auctions.

Investors withdrew an estimated $35.3 billion from Russia from Aug. 8, the day Russian forces invaded Georgia, to Sept. 5, BNP Paribas said Thursday, Bloomberg reported.

The ruble fell Thursday to a 13-month low.

In televised opening remarks to the Kremlin meeting, which was ostensibly called to discuss the creation of an international financial center in Moscow, Medvedev reiterated for a second day running that he saw the stock market slump as a temporary one.

The market slump "obviously does not reflect the objective state of the economy," Medvedev said. "The Russian stock market remains very promising for investments, and serious investors understand this."

Medvedev acknowledged that the talk about developing a leading financial center came at a difficult time for international markets but said "for that very reason it's becoming all the more important."

In laying out plans to increase transparency on financial markets, Medvedev also appeared to refer to current liquidity problems.

"The likelihood of an unbalanced inflow or outflow of funds could cause problems, as regards banking liquidity, increasing inflationary risks and the economy overheating," Medvedev said.

Earlier in the day, Finance Minister Alexei Kudrin said that among the measures being considered to boost liquidity were injections from the Pension Fund and the National Welfare Fund on the domestic market.

"In the future this will be possible, if it becomes necessary," Kudrin said.

But rating agency Standard & Poor's said in a note Thursday that Russia's BBB+ sovereign credit rating would be jeopardized by such support measures.

Medvedev's comments got a mixed reaction from investors and analysts.

"I think right now we need more powerful, more concrete arguments to support the market," said Natalya Orlova, chief economist at Alfa Bank.

Medvedev's talk of developing an international financial center seemed a little mistimed, given that it required "a very stable financial market," she said.

"Realistically speaking, Russia needs to work on fundamental changes in the economy to implement this financial center," she said, referring to reforms on infrastructure and regulations.

Some investors remained optimistic that words of confidence from the Kremlin might help matters.

"It is helpful that they seem to care and that they think about what needs to be done for the Russian market to function more efficiently," said Mattias Westman, chief executive of Prosperity Capital Management.

James Fenkner, director at Red Star Asset Management, said the late-afternoon stock falls were recognition that no recovery was yet in sight.

"After such massive moves the expectation was that the market would bounce," Fenkner said. "It's the same story it's been for at least the past month. There are a lot of forced sellers in the market and folks trying to cover positions."