At least eight auto makers are in negotiations to offer HD Radio receivers on 30 platforms, says Robert Struble, CEO of iBiquity Digital Corp., inventor of the high-definition digital radio technology.

Struble declines to name the auto makers because negotiations still are in progress. At present, only BMW AG offers HD Radio as an option in its '06 7-Series and 6-Series models.

The iBiquity chief reveals the negotiations at a press conference in New York at which eight of the top U.S. radio chains announce a $200 million strategic alliance to persuade car makers, receiver manufacturers and electronic retailers to strengthen their support of the new technology.

There currently are more than 600 radio stations transmitting HD signals, Struble says. The alliance seeks to speed the conversion of additional stations owned by their members and other station owners.

Alliance members vowed to encourage automotive manufacturers to speed up their plans for using HD Radio receivers in their vehicles. At the same time, the alliance will seek to persuade radio manufacturers to lower prices on HD receivers. The HD receiver offered by BMW is a $500 option.