US STOCKS-Market points up after Buffett's Goldman investment

* Buffett investment in Goldman helps futures

* Bernanke, Paulson return to Capitol Hill on bailout

* Data on existing-home sales, energy inventories on tap (Recasts first paragraph, updates prices)

By Ellis Mnyandu

NEW YORK, Sept 24 (Reuters) - U.S. stocks headed for a higher open on Wednesday after Warren Buffett made a $5 billion investment in Goldman Sachs Group Inc (GS.N) late on Tuesday, buoying sentiment in the beleaguered financial sector.

Additionally, Japan's No. 3 bank, Sumitomo Mitsui Financial Group (8316.T), plans to invest in Goldman Sachs, Japanese media said, in what would be the third big Japanese investment this week on Wall Street.

Before the bell, shares of Goldman Sachs jumped nearly 5 percent to $130.85, while rival Morgan Stanley (MS.N) rose 4.6 percent to $29.30. JPMorgan Chase (JPM.N), the No. 3 U.S. bank, were up 2.3 percent at $41.48.

A rise on Wall Street would help reverse the worst two-day slide in six years.

But even as the Goldman Sachs news suggested confidence, investors worried congressional wrangling could delay or weaken the proposed $700 billion plan to rescue the financial sector, increasing unease about the struggling U.S. economy.