Beleaguered auto-parts supplier

Delphi

(DPH)

reported a wider-than-expected first-quarter loss Friday and said auto production at its largest customer,

General Motors

(GM) - Get Report

, could be 8% below its prior forecast for 2005.

Delphi lost $409 million, or 74 cents a share, in the quarter, compared with earnings of $53 million, or 9 cents a share, last year. The latest quarter included a $31 million restructuring charge, before which it lost $378 million, or 68 cents a share. Sales fell 7% from a year ago to $6.9 billion.

Analysts surveyed by Thomson First Call were forecasting a loss of 31 cents a share on sales of $6.8 billion.

For the second quarter, the company expects sales of $7.2 billion to $7.4 billion and slightly higher margins than were posted in the first quarter. Analysts are forecasting a loss of 22 cents a share on sales of $7.2 billion.

For the full year, Delphi now says it won't meet its previous guidance for a loss of $350 million. The company lowered its estimate of GM North America auto production to 4.5 million to 4.6 million units, down 6% to 8% from its previous estimate, and said the shortfall will cut $900 million to $1.1 billion from its own revenue.

"Our earnings and operating cash flow are certainly exposed to this revenue decline due to the fixed nature of our U.S. cost structure," the company said. "While we are beginning to gain traction on our material cost reduction initiatives, to date Delphi has had slower-than-expected success in these areas."

The stock closed Thursday at $3.40.