Sirius, XM Can't Merge: FCC Chief

Shares of Sirius Satellite Radio (SIRI Quote) and rival XM (XMSR Quote) tumbled Wednesday after the chairman of the Federal Communications Commission said agency rules wouldn't allow the two to merge.

A potential merger of the companies has been the subject of repeated speculation in recent months, but Bloomberg quoted FCC Chairman Kevin Martin as saying that existing regulations prohibit a single owner for the two satellite-ratio operators.

Martin made the comments following an FCC meeting. Sirius was dropping 5.5% to $3.92. XM was slumping 7.6% to $15.83.