Updated from 8:25 a.m. EDT

Stocks in New York opened lower Monday, as traders assessed the Treasury Department's massive weekend bailout plan for financial firms.

The

Dow Jones Industrial Average

shed 54 points to 11,335, and the

S&P 500

slipped 9.7 points to 1245. The

Nasdaq

gave back 17 points to 2257.

On Friday, the three major indices finished substantially higher. Financials led the rally after the

Securities and Exchange Commission

temporarily banned short-selling of 799 stocks in the sector. The Treasury announced that over the weekend it would iron out a plan to provide hundreds of billions of dollars to U.S. banks and brokerages to try to avert further damage from the credit crisis.

The

New York Stock Exchange

on Monday extended the short-selling ban to 30 more companies that have significant financial operations. The list includes

General Motors

(GM) - Get Report

and

General Electric

(GE) - Get Report

.

Over the weekend, the

Treasury Department

drafted a plan to lift as much as $700 billion in mortgage debt from financial-sector balance sheets.

On Sunday, the

Federal Reserve

said that

Goldman Sachs

(GS) - Get Report

and

Morgan Sanley

(MS) - Get Report

would become bank holding companies instead of investment banks. The change subjects the pair to increased government oversight and stricter capital requirements.

Goldman and Morgan

had been the final two large, independent brokerages after

Lehman Brothers

went bankrupt and

Bear Stearns

and

Merrill Lynch

(MER)

merged with large banks.

CNBC

subsequently reported that Morgan Stanley would probably not be merging with

Wachovia

(WB) - Get Report

following the

Fed's announcement

.

Separately, Japanese bank

Mitsubishi UFJ

(MTU)

announced early Monday it would buy a 10% to 20% stake in Morgan Stanley. Such an investment could be worth as much as $8.4 billion.

Outside the financial sector, software maker

Microsoft

(MSFT) - Get Report

announced a $40 billion

share buyback

program and said it would raise its quarterly dividend to 13 cents from 11 cents.

Shifting to commodities, crude oil was gaining $1.92 to $106.47 a barrel. Gold was adding $20.80 to $885.50 an ounce.

Longer-dated U.S. Treasury securities were falling in price. The 10-year was down 14/32 to yield 3.86%, and the 30-year was down 27/32, yielding 4.43%. The dollar was declining vs. its major foreign competitors.

Abroad, many foreign markets were marching higher. The FTSE in London and the DAX in Frankfurt were both climbing, and the Nikkei in Japan and the Hang Seng in Hong Kong finished on the upside.