WASHINGTON — Less than six weeks after filing for protection from its creditors, General Motors Corp. is expected to emerge from bankruptcy today as a leaner, greener company, but saddled with doubts as to whether it can turn a profit for its new owners, the American public.

Amid speculation that GM will change the blue in its classic logo to green to highlight its environmentally friendly rebirth, the company will have a tough time turning its bottom line from red to black, analysts said. Vehicle sales have plummeted worldwide because of the global recession. And GM's image, already battered after decades of declining quality, has been further damaged as it was forced to plead with the government for billions in taxpayer money to keep it from the corporate scrap heap.

"It's impressive that they got through bankruptcy that quickly," said Karl Brauer, editor of auto Web site Edmunds.com. "But ... when it takes you three or four decades to tear down a car company's image, it takes more than 39 days to bring it back."

Wooing back U.S. auto buyers is the largest challenge facing GM, analysts said.

Consumer research firm J.D. Power & Associates reported last month that the quality gap between U.S. automakers and their foreign rivals is as small as it's ever been.

"The problem is that the American public isn't ready to believe that, and that's the most important issue that GM faces," said John Wolkonowicz, an analyst at IHS Global Insight. "How do you bring consumer perception in line with the reality of what a GM product is today?"

In the 1950s and '60s, about half the cars sold in the U.S. carried a GM nameplate. The company's dominance waned as consumers migrated to foreign makes, mostly Japanese. Through the first six months of this year, GM's U.S. market share had shrunk to less than 20 percent.

The world's largest company as recently as a decade ago, GM will emerge from bankruptcy smaller in every way.

The restructuring will allow the automaker to dump most of its onerous debt load — it entered Chapter 11 with $176 billion in liabilities and will exit with just over $48 billion in debt.

But GM also is cutting 21,000 salaried and hourly jobs by the end of next year. It will close 13 plants and is pulling out of its joint venture with Toyota Motor Corp. GM has struck deals to sell three of its brands — Hummer, Saturn and Saab — and has pulled the plug on Pontiac. And the company is severing ties with 2,400 of its 6,000 dealers.

The path was cleared for GM to shed most of its debt and many unwanted assets when a Bankruptcy Court order approving the sale went into effect yesterday over the objections of some creditors and small labor unions.

The longtime symbol of American capitalism will emerge as a ward of the state, at least temporarily. The U.S. Treasury Department, which has poured $50 billion into the company, now owns 60.8 percent of it. The Canadian government, which provided $9.5 billion, receives an 11.7 percent stake. And the retiree health care trust of the United Autoworkers union now owns 17.5 percent of the company in exchange for forgiving about $10 billion in debt.

As he pushed GM into bankruptcy June 1, President Obama vowed the government would not become involved in the company's daily management. The administration plans to sell its stake eventually, after the new GM goes public in 2010.

The impact of government ownership will be clear today as chief executive Fritz Henderson and incoming board chairman Edward E. Whitacre Jr. announce further changes, including an expected cut in white-collar jobs. Henderson took over in the spring after the Obama administration forced out former CEO Rick Wagoner.

GM is counting on a lineup of new or redesigned vehicles drawn from its remaining Chevrolet, Cadillac, GMC and Buick brands. Among them are the Buick Lacrosse and Chevy Malibu sedans; the company's upcoming global compact, the Chevy Cruze; and the resurrected Chevy Camaro muscle car.

But Rep. Gary Peters, D-Mich., who along with other Midwestern lawmakers pushed for government aid for GM and Chrysler, said GM's emergence from bankruptcy will start a positive new chapter for the industry.

"Decades from now, our nation will be glad we did not let a global credit crisis put an end to the American automobile," he said.