NEW YORK (Bloomberg) — A General Motors Corp.-Chrysler LLC combination wouldn't win the support of auto unions in the US and Canada because jobs would be lost, the labour groups' presidents said.

"We have not had any discussions formally with any of the companies," United Auto Workers President Ron Gettelfinger said Tuesday on Detroit radio station WWJ. "I personally would not want to see anything that would result in a consolidation that would mean the elimination of additional jobs."

The comments by Gettelfinger and Canadian Auto Workers President Ken Lewenza follow reports that GM and Chrysler have discussed a possible merger. Cerberus Capital Management LP, which owns 80.1 percent of Auburn Hills, Michigan-based Chrysler, has held discussions with Detroit-based GM about combining the companies, five people with knowledge of the talks have said.

"I think you could convince them," David Cole, chairman of the Center for Automotive Research in Ann Arbor, Michigan, said of the unions. "Profitability over the long term is the only job security these guys have." Neither GM, the largest US automaker, nor No. 3 Chrysler has commented on whether such talks have occurred. A merger or partnership might let the two companies reduce costs by trimming overlapping operations and consolidating plants, while probably not solving their financial problems, analysts have said.

Lewenza said in an interview that the CAW hasn't been approached by either company about merger discussions.

"Somebody has to tell me where the last time there was an auto merger that was good for workers," Lewenza said. "It would be troublesome for us because we see a lot of similarity in their products and obviously some of those products would be lost," with jobs cut along with them.

Deutsche Bank analyst Rod Lache estimated that a combined company might produce $6 billion in savings while still failing to assure "long-term health."

"It is unlikely that the combined entity would be able to maintain 11 distinct brands and roughly 30 percent market share," the New York-based analyst wrote in a note to investors.