Delphi Corp. (DPHIQ) on Wednesday said its net loss shot wider in the quarter before the auto parts maker filed for bankruptcy, pressured by production cuts at former parent General Motors Corp. (GM) and high materials costs.

The loss widened to $788 million, or $1.40 per share, in the third quarter, from $119 million, or 21 cents per share, a year earlier, Delphi said. Revenue fell 5.4 percent to $6.28 billion from $6.64 billion.

Delphi, the largest U.S. auto parts supplier, on October 8 filed the biggest bankruptcy protection case in U.S. automotive history, blaming high wage costs for choking North American operations and masking strong performances in other regions.

Troy, Michigan-based Delphi has asked its unions for steep wage and benefit cuts and work rules changes to slash U.S. costs and expects to make significant reductions in its U.S. operations. International operations are not part of the reorganization.