General Motors Corp., New York, plans to help shore up its $60 billion in U.S. pension assets by raising about $10 billion through the sale of bonds and convertible securities. GM's pension plans were underfunded by $19.3 billion at the end of 2002. The company contributed $5.8 billion to the funds in 2002 and an additional $1.2 billion in GM Class H common stock earlier this year. Company officials said in a statement they expect to contribute most of the proceeds from the bond offerings to the pension funds. In 2002, GM had said it would contribute about $15 billion to its pension funds by 2007.