The U.S. auto industry needs even more help from the government to survive than originally thought.

General Motors on Tuesday said it could need up to $30 billion from the Treasury Department to keep operating. Included in that amount is $13.4 billion the company has already received. Previously, GM had said it could need as much as $18 billion.

General Motors Corp. and Chrysler LLC said Tuesday they'll need billions more in government loans than they predicted just two months ago. The two automakers also plan further job cuts and additional curtailment of auto production.

Both companies plan to reduce the number of models they offer to car buyers over the next few years.

Meanwhile, the United Auto Workers union said it has reached a tentative agreement with Chrysler, GM and Ford Motor Co. on modifications to existing labor contracts.

Acknowledging that industry conditions are worse than expected when it made the case in December for a government bailout, GM said it could run out of money by March without new funds from the government. The latest request includes $9.1 billion in new loans and a $7.5 billion credit line.

Chrysler requested an additional $5 billion from Treasury. It originally said it would need $3 billion more. The company had already received $4 billion.