Saab Automobile expects within the next few weeks to narrow its focus to one of three final bidders and complete a sale by early summer, a spokeswoman tells Ward’s.

The Swedish auto maker won’t say who the three finalists are in the sale process, which started with 27 interested parties, was narrowed to 10 and finally culled to three earlier this month.

Fiat Auto Group has expressed interest in acquiring Saab from General Motors Corp. in conjunction with a bid to take a controlling stake in GM’s Adam Opel GmbH subsidiary in Germany, but Saab spokeswoman Gunilla Gustavs won’t say whether Fiat is considered one of the three finalists. Reports indicate a buyer for Opel could be determined as early as this week, but any transaction involving Saab is expected to be kept separate from such a deal.

Gustavs declines to reveal whether the final three Saab bidders are auto makers, independent investors, other types of companies or a combination of all three.

“We’re not commenting further on the final three, although it was quite a mix when we were at 10 (bidders),” she says.

Saab has been in bankruptcy in Sweden since Feb. 20, which, like Chapter 11 in the U.S., has provided the auto maker with protection from creditors while it restructures and works to extract itself from GM.

The auto maker now believes it has its vehicle-development process sufficiently separated from GM operations, with agreements in place for technology sharing on the next-generation 9-5 and upcoming 9-4X cross/utility vehicle due in the ‘10 model year and a more autonomous engineering team set to tackle future programs.

The new 9-5, based on GM’s Epsilon platform, is heavily reliant on Opel for its engineering, while development of the Theta-based 9-4X, to be build in Mexico, is centered in North America.

Saab’s business plan calls for the auto maker to concentrate its production at the Trollhattan, Sweden, assembly plant, where it currently builds the 9-3 and now is looking to add the next-generation 9-5, as well.

The new 9-5 was to be made at Opel’s Russelsheim, Germany, plant, “but we’re now looking at bringing that back (to Trollhattan),” Gustavs tells Ward’s. “That would better utilize our production capacity.”

Powertrains would continue to be sourced from GM, she says.

Once GM picks a buyer for Saab and final negotiations get under way, probably sometime in June, work will begin to align operations with those of the purchaser.

“We have transition services put in place so that under the new owner we can set things up,” Gustavs says, adding, once final negotiations begin Saab will be able to “show the new owner how (the integrated company) will look.”

The Swedish government may have some say in who buys the auto maker. It tentatively has agreed to guarantee a SK5 billion ($650 million) line of credit from the European Investment Bank provided it is convinced the marriage has a chance of succeeding.

Gustavs says there are two primary criteria the successful bidder must meet: It has to be financially strong and it must be willing to take a long-term view on Saab. That includes buying into the vision of a more Swedish Saab, with design, engineering and production once again centered in its home country.

“They’ll have to see the benefits of a concentrated, Swedish operation, with a tighter brand and the ability to make quick decisions.”

Saab sales have been adversely affected in Sweden and the key U.S. market ever since the auto maker was put on the selling block.

“We knew we would take a hit,” Gustavs says. “But we feel very optimistic now. We’re hopeful that this is going to turn out well and give us a new start. It’s been quite a journey.”

It is uncertain what effect a Chapter 11 filing by parent GM would have on the Saab sale. GM has until June 1 to meet U.S. restructuring requirements if it is to avoid bankruptcy.

“I don’t think there will be an immediate impact,” Gustavs says. “It’s too early to say if it will have an impact at all.”

Saab’s reorganization plan calls for the auto maker to begin operating in the black in 2011.