One of the first hurdles General Motors Corp. (GMGMQ) faces after exiting bankruptcy Friday will be dealing with a battered supplier base littered with companies that are either in or close to filing for Chapter 11.

Parts companies are the backbone of the automotive industry around which the daily operation of assembly cars and pickup trucks works. Any disruption in the flow of parts from any supplier can shut down assembly plants within a matter of hours.

GM, which is planning to resume production as General Motors Co. next week, surprised many industry analysts by exiting reorganization in 40 days. But the quick exit brings no real relief for its suppliers who have been cash-strapped for months amid plant shutdowns by GM and Chrysler Group LLC.

Chrysler alone kept its plants down for almost two months during its bankruptcy reorganization.

The new GM enters an environment where eight major suppliers have filed for bankruptcy. Lear Corp. (LEAR), one of GM's biggest automotive seat and interiors providers, filed for Chapter 11 earlier this week.

"Supplier health will be the wild card for the next 90 days, not only for GM but all of the auto makers," said Mike Robinet, vice president of global vehicle forecasts for CSM Worldwide.

"They are going to have to keep watch on them. If there is any good news, the quick resolution by GM and Chrysler may help to reduce the trepidation in the capital markets about the auto industry."

Ford Motor Co. (F), which hasn't sought bankruptcy, sends teams of financial advisors and engineers to multiple suppliers weekly to help keep their operations running. Ford has also provided funding to some of its suppliers including Visteon Corp. (VSTN)

"I think many suppliers have adapted quite well to a difficult environment with very aggressive plans to exit bankruptcy themselves and continue to be world class suppliers," GM Chief Executive Officer Fritz Henderson said Friday. "Our biggest challenge from a supply base continues to be supporting Delphi Corp. in their emergence from bankruptcy."

Bids to buy Delphi's assets are due Friday. The front-runner is considered the California equity firm Platinum Equity LLC. Platinum negotiated with Delphi, GM and the Obama administration to buy the majority of Delphi for $3.6 billion. U.S. Bankruptcy Judge Robert Drain ruled that there must be a formal bidding process with all offers due Friday.

While GM may be concentrating on Delphi, it also faces another potential problem from American Axle & Manufacturing Holding Corp. (AXL). The company, which equips almost all of GM's pickup trucks with axles, received a waiver on loan terms earlier this week and has until July 30 to renegotiate its terms. The supplier had about $280 million in cash as of June 30.

American Axle alone shutdown 29 of GM's assembly, stamping and transmission facilities last year when workers walked off the job Feb. 26 over a wage and benefit dispute. GM shut its first plant about 24-hours after the strike began.

-By Jeff Bennett; jeff.bennett@dowjones.com; 248-204-5542