WASHINGTON — Nearly three years after Delphi Corp. filed for bankruptcy, its prospects for emerging soon remain deeply uncertain as the Troy, Mich.-based auto parts supplier faces growing pressure from investors and the government.

Delphi remains mired in Chapter 11 bankruptcy because it cannot raise the money it needs to operate outside court protection from creditors. The company is seeking court approval to borrow an additional $300 million from General Motors Corp., but investors are objecting to Delphi’s continued reliance on its former parent when GM is facing deep financial trouble of its own. A court hearing on the loan that was scheduled for Tuesday has been postponed until next month.

There also are significant questions about Delphi’s ability to meet its pension fund obligations. The Pension Benefit Guaranty Corp., which insures the nation’s pension plans, is urging Delphi and GM to shift some of that burden to GM.

Delphi was expected to emerge from bankruptcy in April, but says it’s unsure if it will happen this year. The exit plan derailed when a group of investors led by Appaloosa Management LP, Delphi’s largest shareholder, pulled out of a deal to pump $2.55 billion in the company. Delphi sued to force Appaloosa to honor the agreement.

Delphi creditors also sued Appaloosa, saying too much time had been wasted and Delphi was forced to find new financing at a difficult time in the markets. The creditors asked the court to rescind approval of Delphi’s reorganization plan because there was “no possible alternative source of equity financing that could save the plan.”

Appaloosa President David Tepper, who has said Delphi failed to live up to terms of the agreement, did not return a call for comment.

What comes next is uncertain. Delphi has reduced the amount of cash it is seeking to exit bankruptcy, but tight credit and the sharp downturn in the U.S. auto market make it unlikely the company will find new suitors. The company could continue selling — or close — more of its operations to emerge as a smaller, profitable company. Or it could be forced to liquidate, an option few are considering.

For now, it turns to GM, which has loaned Delphi $650 million and is prepared to add $300 million. U.S. Bankruptcy Judge Robert Drain has set a Sept. 23 hearing on the loan, which has been criticized by one of Delphi’s largest investors.

That loan is “a Band-Aid (albeit an enormously expensive and porous Band-Aid),” Highland Capital Management LP said in a court filing last week. Highland said Delphi is losing “staggering sums of money” at an “alarming rate,” noting that it burned through $960 million in cash in the first six months of the year.

Highland argues that Delphi is losing money because it is selling parts to GM below its costs and should instead focus on its profitable overseas operations. But David Healy, an auto analyst at Burnham Investment Research, said GM is paying premium prices for Delphi parts to support the struggling supplier. “Delphi is the problem for GM that just won’t go away,” Healy said Friday.

Pension agency ‘concerned’

One of Delphi’s immediate challenges is a September deadline to make $2.4 billion in payments to its pension plan. Delphi has skipped $2.3 billion in payments since filing for bankruptcy under a waiver granted by the Internal Revenue Service. Earlier this year, Delphi let the waiver expire.

The Pension Benefit Guaranty Corp. has slapped liens on many of Delphi’s foreign assets and urged the supplier to transfer $1.5 billion of its pension obligations to GM by Sept. 30. The two companies are in talks on the terms of a deal.

“The negative consequences will be severe for all of Delphi’s stakeholders,” if the obligations are not met, PBGC Director Charles Millard wrote in a letter this month to Delphi Executive Chairman Robert S. Miller and GM Chief Operating Officer Fritz Henderson. He said the agency is “increasingly concerned.”

Delphi could also owe more than $3 billion in penalties for failing to make its pension payments, and the PBGC could make a claim of up to $8 billion against Delphi’s assets if the supplier terminated its pension plans. “The impact of a Delphi plan failure on the already overburdened pension insurance system would be staggering,” Millard wrote.

Delphi said in a securities filing that it is in talks with GM about solutions to the pension problem, including transferring certain Delphi assets and liabilities to GM.

Kirk Ludtke, an auto analyst at CRT Capital, said he suspects Delphi “allowed its payment waiver to lapse to put pressure on GM.”

Bankruptcy takes toll on GM

Delphi rocked the auto industry when it filed for Chapter 11 bankruptcy protection on Oct. 8, 2005. Since then, it has lost $11.8 billion, closed 21 of its 29 U.S. factories and cut its hourly work force by nearly 50 percent, and its salaried work force by almost 40 percent.

The supplier has spent $3 billion to offer buyouts and early retirements to thousands of hourly workers. This month, it reported a $551 million second-quarter loss and said it would cut 600 more salaried workers, mostly in Indiana.

The bankruptcy has taken a toll on GM as well. The automaker has booked $11 billion in expenses connected to Delphi and could take on more financial responsibility.

“GM and Delphi continue to work together toward a successful Delphi exit from bankruptcy,” GM spokeswoman Renee Rashid-Merem said.

But GM has a financial crisis of its own. It lost $15.5 billion in the second quarter as it copes with plunging U.S. auto sales.

Delphi is tight-lipped about its progress in bankruptcy. Spokesman Lindsey Williams said the company continues to talk with GM, its unions, government agencies and others about resolving the pension funding problem.

“We do not provide commentary regarding ongoing negotiations,” he said. Williams also said Miller planned to remain with Delphi through the bankruptcy.

Despite the delays and continuing problems, Delphi executives say the company will emerge from bankruptcy, but as a much smaller, more profitable company.

It has been selling off underperforming units while cutting costs and diversifying its business. Last year, 37 percent of Delphi’s $22.3 billion in business came from GM, down from 45 percent in 2005.