Satellite radio service provider Sirius Satellite Radio Inc. said Tuesday (Jan 2) it grew its subscriber base to more than 6 million, roughly at the midpoint of a previous projection.

Also, based on preliminary fourth-quarter financial results, Sirius believes it reached positive free cash flow for the first time. Free cash flow represents the cash that a company is able to generate after laying out the money required to maintain or expand its asset base. Free cash flow is important because it allows a company to pursue opportunities that enhance shareholder value.

Sirius lowered its subscriber growth outlook in December, projecting 5.9 million to 6.1 million subscribers by year-end, down from a previous forecast for 6.3 million subscribers.

The New York company ended the year with 6.02 million subscribers, up 82 percent from 3.32 million subscribers last year.

Shares of Sirius were trading at $3.55 in the after-hours trading session, up a penny from Friday's closing price of $3.54 on the Nasdaq Stock Market.