• Up to three potential Saab buyers

Chief executive of Swedish car maker Saab's owner, General Motor, said Monday that a bankruptcy filing appears increasingly likely as the auto giant struggles to radically restructure.

"Given the objectives that we've set for ourselves it's more probable that we need to accomplish our goals in a bankruptcy," chief executive officer Fritz Henderson said in a conference call with reporters.

"But there's the still an opportunity and still a chance for it to be done outside the court process."

GM, which is keeping its operations afloat with more than 15 billion dollars in US government loans, faces a June 1 deadline to slash costs, shed brands, and reach a deal with its union and bondholders to reduce its massive debt load.

Henderson said GM does not plan to modify its debt-to-equity offer despite public protest from bondholders unwilling to accept the current terms.

Rival Chrysler was recently forced to seek bankruptcy protection after its creditors balked at similar terms but Henderson said he saw little cause for optimism in the fact that those creditors dropped their objections on Friday.

"I've got my hands full here and the facts are different," he told reporters.

"Chrysler had 46 secured lenders. We've got thousands of unsecured bondholders."

The automaker is currently working to determine whether its operations outside of the United States would also need court protection should it be forced into bankruptcy, Henderson said.

"It's not a foregone conclusion that a US filing would follow by filings in other countries," he said.

"In general our preference would be to avoid that but in a number of cases it might be necessary. At this point the analysis is being done country by country."

GM hopes to have a deal before the end of the month to sell a major stake in its European business and is "speaking with multiple bidders," Henderson said.