Nissan officials counter that the line speed is about the same as other American auto manufacturers.

Nissan officials said the company had also returned to the black on a consolidated basis.

"We can always buy more parts," a senior Nissan official said.

Nissan officials, however, have argued that they, and G.M., should be worried more about Toyota.

Renault is expected to have a board meeting on Tuesday, after which it may announce a deal, Nissan officials said.

Nissan officials have made similar changes to reduce production costs of the new Altima, which goes on sale July 10.

Mr. Hannun, the Nissan official, declined to disclose the cost of the auto maker's commercial.

Nissan officials have also been lowering expectations about the company's profitability in the fiscal year that ended on March 31.

For their part, Nissan officials insist there are clear differences between the brands.

These attempts to create what Nissan officials call a "dream factory" attest to a serious problem.