A U.S. bankruptcy court judge opened a hearing on Tuesday morning on government-backed plans by General Motors Corp to seek approval to sell its main assets to a New GM.

The hearing began around 11 a.m. EDT, more than an hour late, after a delay to sort out communications problems for lawyers, creditors and others who hoped to dial in to the courtroom to hear Judge Robert Gerber speak.

A lawyer for GM, Harvey Miller of Weil Gotshal & Manges, opened by saying there had been progress made on some of the objections by customers, employees, former employees, creditors and others, while some other objections were still unresolved.

GM Chief Executive Fritz Henderson and dozens of lawyers gathered in U.S. Bankruptcy Court in Manhattan for the sale hearing. The automaker is seeking court approval for the sale just 30 days after filing for Chapter 11.

Under the deal, brokered by the Obama administration's autos task force, the company would sell its assets under Section 363 of the bankruptcy code to a New GM and continue to operate its best assets, including Chevrolet and Cadillac, while the U.S. Treasury would provide billions of dollars in financing.

GM's old assets would remain behind in bankruptcy court to be liquidated.

Outside the courthouse, about 75 union-affiliated protesters carried placards and chanted Save our benefits.

The deal faces several objections from bondholders and those concerned about the fate of GM's dealers, but no competing bidders have emerged as an alternative to the U.S. government's $60 billion financing for GM, including a proposed equity investment of $50 billion that would give the U.S. Treasury a 60 percent ownership stake.

If the sale goes through, it would mark the second big victory for the Obama administration's autos task force, which successfully brokered the sale of Chrysler LLC to a group led by Italy's Fiat SpA. The U.S. Supreme Court cleared the way for that deal to go through on June 9.

GM has said in court papers that the sale would avoid a systemic failure for the U.S. auto industry.

The company has shut 13 of its U.S. assembly plants for up to 11 weeks to cut production and run down inventory while it seeks court approval for the sale.

GM has said more than 50 percent of its bondholders support the deal.

In addition to the 60 percent U.S. government stake in the New GM under the plan, the United Auto Workers union would gain a 17.5 percent stake, the Canadian government would own about 12 percent, and GM bondholders are expected to get about 10 percent.

A group of small bondholders, which calls itself the Unofficial Committee of Family & Dissident GM Bondholders, has said it expects to challenge the sale.

Several other individual bondholders have filed objections to the sale, along with the state of Texas which contends the sale illegally challenges state laws on dealerships, and a group representing about 300 Americans with lawsuits against GM for alleged product defects.

GM, however, resolved a key objection from nine state attorneys general over the weekend, saying the New GM would accept liability for future product defects. The company also said it would address objections raised by more than 20 of its parts suppliers.

The case is In re: General Motors Corp, U.S. Bankruptcy Court, Southern District of New York, No. 09-50026.

(Reporting by Emily Chasan and Caroline Humer, editing by Matthew Lewis)