Shareholders of both Sirius Satellite Radio and XM Satellite Radio separately approved Sirius' $5 billion acquisition of XM on Tuesday.
Now the companies just need approval from the Department of Justice and the Federal Communications Commission before they can make the deal final.
But approval from these agencies is far from guaranteed. The FCC has been examining the deal very closely. Originally, the agency barred satellite radio companies from combining. But the rule could be changed, especially as satellite radio faces more competition from Internet music services, music playing phones and online music stores like Apple's iTunes that allow people to play music on iPods.
Sirius and XM argue that together they could offer consumers more choices and pricing options. The companies each offer packages that include music, talk, sports, and other programming for about $13 per month. If the deal is approved, the companies say they can offer plans starting at around $7 per month.
Some analysts expect the FCC to make a decision on the deal in early December.