NEW YORK NEW YORK, Sept 29 (Reuters) - U.S. stock index futures slid on Monday, tracking a global equity sell-off, as two European banks and another U.S. bank became the latest victims of the credit turmoil and investors worried if a proposed U.S. rescue would stem the contagion.

Moves by the Bank of England, the European Central Bank and Asian authorities to pump more cash into banks failed to calm jittery investors. In Britain the government took over troubled mortgage lender Bradford & Bingley.

In addition, Belgium, the Netherlands and Luxembourg acted to partly nationalize banking and insurance group Fortis, suggesting the European sector's troubles were spreading. Worries about the financial sector also drove losses across Asia.

"The U.S. rescue plan is basically done. The news out of Europe this morning is what's really taking a toll on the market. It's one more indication of how serious the situation has become," said Peter Cardillo, chief market economist at Avalon Partners in New York. "The fear is about contagion."

S&P 500 futures slid 21.20 points and were below 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 tumbled 184 points and Nasdaq 100 dropped 30.25.

The declines suggested major equity indexes will see declines of at least 2 percent or more at the open.

Shares of Wachovia Corp tumbled 60 percent to $4 before the bell. According to sources familiar with the situation, the sixth-largest U.S. bank by assets is in buyout talks with rivals, including Citigroup and Wells Fargo.

In Washington, congressional leaders from both parties said they reached a tentative agreement on the $700 billion bailout plan aimed at cleaning up banks' balance sheets of soured mortgage-related debt and unclogging the financial system.

Republican Sen. Judd Gregg of New Hampshire said he expected the House to vote on the bill on Monday, while Senate Majority Leader Harry Reid said the Senate could take it up by Wednesday. For details, see ID:nLT387116

Bradford & Bingley became the second British bank to be nationalized since the global credit crunch began 13 months ago.

After emergency talks with ECB President Jean-Claude Trichet on Sunday, governments agreed to inject $16.4 billion into Fortis in the first major bank crisis to hit the euro zone from the global turmoil spawned by U.S. subprime mortgages and the housing downturn.

Monday's economic calendar includes data on U.S. personal income and spending at 8:30 a.m. (1230 GMT).

U.S. stocks ended mostly higher on Friday as big bank shares staged a late rally on hopes lawmakers were close to agreeing on financial-sector rescue plan.

But tech shares fell, keeping the Nasdaq in the red, after a disappointing outlook from BlackBerry maker Research in Motion.

(Editing by Kenneth Barry)

((Ellis.Mnyandu@thomsonreuters.com; +1 646 223 6085; Reuters messaging:ellis.mnyandu.reuters.com@reuters.net)) Keywords: MARKETS STOCKS

Chuck Mikolajczak

The copying, republication or redistribution of Thomson Financial News Content, including by framing or similar means, is expressly prohibited without the prior written consent of Thomson Financial News.