Stock index futures rose on Wednesday, signaling Wall Street will extend Tuesday's strong advance on bets Washington will act soon to restore confidence in banks by relieving them of money-losing assets.

A day after a surge in financial stocks fueled the biggest one-day rally since late November, banks again underpinned pre-market gains, with Bank of America up 6 percent to $5.08 and Citigroup rising 10.3 percent to $1.60.

Further rises would extend gains seen in Asia overnight and then in Europe on Wednesday and mark the first back-to-back advance for the benchmark S&P 500 <.SPX> index in a month.

U.S. Treasury Secretary Timothy Geithner pledged on Tuesday to do what is necessary to jolt the economy out of recession in an interview on the Public Broadcasting Corp's Charlie Rose Show.

Andre Bakhos, president of Princeton Financial Group in New Brunswick, New Jersey, said: It appears that we will have a continuation of the speculation that the negative conditions, especially in banking will be relieved shortly.

The market is continuing to respond to the one-dimensional fix, which was Citigroup. It will take clarity on the toxic assets plan to add confidence.

S&P 500 futures rose 6.20 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures climbed 43 points, and Nasdaq 100 futures climbed 15.75 points.

Geithner, who has faced criticism for not spelling out details of a proposed public-private fund for buying bad assets from banks, promised action within weeks and said he was moving deliberately to minimize risks of losses for taxpayers.

Relieving banks of toxic, hard-to-sell assets could help stem a wave of writedowns that has fueled unease about banks' stability.

Citigroup's comments on Tuesday that it was profitable in early 2009 and confident about its capital strength sparked hopes some stabilization might be creeping back into banking in a market trying to recover from 12-year lows.

In broker research news, Morgan Stanley recommended investors take on more risk in the bank space given significant price falls and aggressive government action.

UBS raised Hewlett-Packard Co to buy from neutral. The computer maker's stock was up 3.2 percent to $27.90.

Geithner will hold a briefing at 1 p.m. EDT ahead of a weekend meeting of Group of 20 rich nations finance ministers and central bank governors, while on Capitol Hill, Neel Kashkari, interim assistant secretary of the Treasury for financial stability, is due to testify at 10 a.m. EDT on the Troubled Asset Relief Program.

(Editing by James Dalgleish)