Updated from 1:57 p.m. EDT

Stocks in the U.S. rocketed higher Monday, as governments worldwide initiated massive emergency aid packages for struggling banks.

The

Dow Jones Industrial Average

soared 636 points to 9087, and the

S&P 500

jumped 71 points to 970. The

Nasdaq

was better by 133 points at 1782.

During the previous week, the three major indices took a severe lashing as investors worried that stagnant credit markets weren't responding to curative efforts by the U.S. and other governments. The Dow and the S&P each dropped 18%, and the Nasdaq fell 15%.

Over the weekend, central banks across the globe were initiating policies to offer liquidity to banks and bolster lending markets.

The cost of borrowing appeared to relax slightly, as three-month dollar Libor fell 6.6 basis points to 4.75%. Overnight Libor rates were not assessed as U.S. bond markets were closed in observance of Columbus Day.

In the U.S., Interim Assistant Secretary for Financial Stability

Neel Kashkari

said Monday that the Treasury Department had enlisted law firm Simpson Thatcher to advise it on a plan to buy equity positions as a measure in its $700 billion relief package for financial firms.

The U.K. announced a plan to inject capital into three of its struggling banks.

Royal Bank of Scotland

(RBS) - Get Report

,

Lloyds

(LYG) - Get Report

and

HBOS

will get up to $63 billion in government support, the

U.K. government

said.

The leaders of European nations announced that they would engage in a coordinated bailout package for the 15-member Eurozone, and European central banks said they would provide dollar liquidity to banks as needed. The program, with participation from France, Germany, Spain, the Netherlands and Australia, amounts to a $1.8 trillion commitment to guarantee bank loans and buy equity positions in financial firms.

According to a report by

Bloomberg

,

Treasury Secretary Henry Paulson

was looking into a U.S. program to guarantee debt issued by domestic banks following the significant intervention by European governments.

The

Federal Reserve

said it would offer unlimited dollar funding to swap facilities with several European central banks to meet increasing demand.

Paulson has reportedly called an afternoon meeting with key U.S. banking chiefs. According to the

Journal

, the

Treasury Secretary

has invited Ken Lewis of

Bank of America

(BAC) - Get Report

, Jamie Dimon of

JPMorgan Chase

(JPM) - Get Report

, Lloyd Blankfein of

Goldman Sachs

(GS) - Get Report

, John Mack of

Morgan Stanley

(MS) - Get Report

and Vikram Pandit of

Citigroup

(C) - Get Report

to meet at 3 p.m.

Officials are beginning to move with more urgency this week, Doreen Mogavero, CEO and president of Mogavero Lee, wrote in an email. She said she anticipates disappointments as companies report third-quarter earnings and lower guidance.

"I expect lots of volatility for a while and average volume ... barring news situations. I do feel better today than last week, and I think everyone does," wrote Mogavero. She said that although the global economy is on a road to recovery, there will still be bumps on the way.

After massive declines like the ones seen last week, traders are eventually going to jump in on the buy side to take advantage of lower prices, said Tony Dwyer, equity strategist at FTN Midwest Securities. He also said that the equity markets are hoping that actions by central banks are unfreezing credit markets. "Obviously it's working overseas," he said.

Whether stocks can continue rising depends on improvement in the U.S. Treasury bond markets U.S., said Dwyer. "It's all about the credit market," he said.

In company news, mergers and equity investments were dominating the headlines. Japanese bank

Mitsubishi UFJ

(MTU)

closed a deal with

Morgan Stanley

(MS) - Get Report

to buy a 21% stake in the U.S. bank holding company. Shares of Morgan Stanley traded up as much as 80%.

Meanwhile,

Banco Santander

( STD) said it may acquire all of troubled U.S. thrift

Sovereign Bancorp

( SOV).

The Fed said it had cleared the way for

Wells Fargo's

(WFC) - Get Report

purchase of

Wachovia

(WB) - Get Report

.

Outside the financials,

General Motors

(GM) - Get Report

was in discussions with

Cerberus Capital Management

to buy

Chrysler's

automotive operations, according to published reports. Cerberus owns an 80% stake in

Chrysler

.

Waste Management

( WMI) announced it was backing away from its $6.73 billion bid to take over fellow trash hauler

Republic Services

(RSG) - Get Report

.

In analyst actions, Goldman Sachs predicted that the S&P 500 would climb 11% to reach 1000 at the end of the year. There's a high probability of a rally, Goldman said, but the rebound would not mark the beginning of a new bull market.

Merrill Lynch also upgraded Royal Bank of Scotland and German bank

Commerzbank

to buy from neutral.

Barclays

(BCS) - Get Report

,

Credit Suisse

(CS) - Get Report

and

Allied Irish Bank

(AIB)

got bumped to neutral from underperform. Merrill said it revised its ratings on the banks based on valuation.

Among technology shares, Friedman Billings reduced price targets on a wide array of technology companies, including

Microsoft

(MSFT) - Get Report

,

McAfee

( MFE) and

Adobe Systems

(ADBE) - Get Report

.

As for commodities, crude oil settle $3.49 higher at $81.19 a barrel, and gold was lower by $16.50 at $838.50 an ounce.

The market for U.S. Treasury securities was closed. The dollar was falling substantially vs. the euro and pound but rising against the yen.

Europe's exchanges, such as the FTSE in London and the Dax in Frankfurt, were trading higher. In

Asia

, Hong Kong's Hang Seng gained 10%. Japan's Nikkei was closed for a holiday.