The pending combination of XM and Sirius dominated the fourth quarter, as the company's shares fluctuated on any signs that the $5 billion deal would win regulatory approval or fall through. Although shareholders approved the merger in November, investor concerns mounted toward the end of 2007 as the Department of Justice and Federal Communication Commission continued to delay a decision. The companies had hoped to receive regulatory clearance by the end of 2007. Those fears were stoked in mid-December, when Rep. John Conyers, D-Mich., chairman of the House Judiciary Committee, urged the Justice Department not to "rush through" an approval.