General Motors Corp is preparing a new offer to bondholders for a debt restructuring critical to its turnaround that may be far worse than terms the automaker had provided previously, CNBC reported on Thursday.

Bondholders have not been presented with any new terms, a source familiar with GM's talks with bondholders told Reuters, in reaction to the CNBC report.

In negotiations with bondholders, GM last month offered 8 cents cash on the dollar, 16 cents on the dollar in new unsecured debt, and a 90 percent stake in the automaker, according to one person with knowledge of the term sheet.

But CNBC said it had learned that a new offer may include no cash, no new debt and perhaps as little as 10 percent to 20 percent equity in the company. It did not cite a source.

GM, operating under emergency U.S. government loans and seeking additional support, has been told by the Obama administration task force overseeing its bailout that it must cut deeper and faster to continue to receive aid.

The automaker must reach agreements to slash some $28 billion of unsecured debt and restructure funding of a trust for union retirees by June 1. The alternative raised by the task force could be a bankruptcy filing.

GM spokeswoman Renee Rashid-Merem said the task force made it clear that GM must take aggressive actions to restructure its operations and reduce debt on its balance sheet.

We will not comment on the status of bondholder discussions or reports of new proposed terms, she said in a statement.

(Reporting by Soyoung Kim and Walden Siew, writing by David Bailey, editing by Maureen Bavdek)