GM posted a second-quarter net loss of £1.73 billion, compared with a loss of $987 million (£535.2m) over the same period last year.
GM said that globally, its market share fell to 13.8% from 15.1% in the second quarter of 2005. Many analysts think Toyota could surpass GM this year to become the world’s leading automaker.
Last November, GM announced plans to close all or part of a dozen factories by the end of 2008, and eliminate 30,000 jobs. GM also is paying most of the cost of buyouts for workers at Delphi Corporation, its biggest parts supplier, which filed for Chapter 11 bankruptcy protection in October.