Rumors have begun to swirl as to who will replace Mel Karmazin when he steps down as head of SiriusXM Satellite Radio in 2013. Reuters reports that SiriusXM President of Operations and Sales Jim Meyer has emerged as the top internal candidate to become the new CEO. Meyer has been a part of the satcaster since 2004.

"At a company as complex as Sirius, with the satellites, media and automotive parts, gluing it all together is Jim," one source told Reuters. "He is the No. 2 and worked with him closely." Other sources told the news agency that Meyer is one of a number of potential candidates for the job and it is unknown who will be named CEO. SiriusXM CFO David Frear is also considered a top candidate. Frear currently reports directly to Karmazin and has worked at the satcaster since 2003.

Greg Maffei, CEO of SiriusXM's top shareholder Liberty Media, is heading up the search for a new CEO and is reportedly looking at candidates both internally and outside the company. During Liberty's earnings call last month, Maffei said the search for a new SiriusXM CEO could take up to six months.

Reuters notes that Liberty Media owner John Malone has a reputation for hiring big names externally to run his businesses and some sources believe that could be the case again with SiriusXM. Hugh Panero, the CEO of pre-merger XM, has also been mentioned as a potential candidate. One media executive told Reuters Liberty would like to find a "forward- thinking radio or television executive," a la Bob Pittman at Clear Channel.

You can read Reuters' analysis of the situation here.