General Motors (GM) said it has raised its earnings estimates for the first quarter and calendar year 2002, and is boosting its planned vehicle production. The auto and light-truck maker cited better-than-expected industry sales in the United States and strong retail sales of GM vehicles as the reason. The revised outlook came as GM is taking steps to strengthen its balance sheet by $10 billion through a combination of improved cash flow, proceeds from its proposed sale of Hughes Electronics and public securities offerings, GM CFO John Devine said.GM's outlook for first quarter earnings per share is now $1.20, excluding Hughes Electronics and any special charge related to GM's reorganization of its European operations. Its previous estimate for the first quarter, excluding Hughes and the European restructuring charge, was $1 a share.GM's revised estimate for calendar year 2002 is now $3.50 a share, excluding Hughes and the European restructure. The increase of 50 cents from the previous estimate is mostly attributable to expected increases in production to meet better-than-expected retail vehicle demand in U.S.The company said it expects 2002 industry wide sales in the U.S. to reach 16 million vehicles, about one million more than predicted at the beginning of the year.