XM Satellite Radio has raised $326.4 million through a share and note offering, providing funding for the company until 2002.
Competitor Sirius Satellite Radio is seeking $210 million through an offering this month.
The stock offerings come as analysts say that the market for these systems, providing audio entertainment to motorists in the USA, is unproven.
XM Radio plans to launch two spacecraft, Rock and Roll, aboard Sea Launch Zenit 3L boosters this year, with Roll to be launched this month and Rock to follow in May.
The satellites will compete with three spacecraft operated by fellow Washington DC-based company, Sirius.
Source: Flight International