Sirius Satellite Radio on Friday posted a wider quarterly loss on increased marketing costs, but subscribers rose sharply in the run-up to the launch of a new show by radio host Howard Stern. Sirius posted a fourth-quarter net loss of $311.4 million, or 23 cents a share, compared with a loss of $261.9 million, or 21 cents per share, a year earlier. Analysts had forecast a loss of 22 cents a share, according to Reuters Estimates.