General Motors Corp. has poured $1.6 billion into electronic commerce initiatives like the Covisint Internet supplier exchange as part of a four-year drive to integrate its e-business systems, executives of the world's largest automaker said on Thursday. The broad "e-structuring" has generated $800 million in cost savings and helped drive down the automaker's total information technology spending to $3.2 billion annually from $4 billion in 1996, GM's Chief Information Officer Ralph Szygenda told reporters and analysts from around the world at the end of a three-day company presentation here.