The increase in ownership, from 48.1%, was reported in a regulatory filing late Tuesday by SiriusXM.
Liberty's steady march toward full control of SiriusXM is not surprising. The company has publicly stated its intent to acquire a majority share of SiriusXM and is now attempting to follow through with its promise.
When Liberty crosses the 50% threshold, it will need to apply for a transfer of operating licenses from the Federal Communications Commission to fully take control of SiriusXM.
Liberty had tried, and failed, to obtain those licenses in March, when it had 40% of SiriusXM's stock. The FCC responded that Liberty needed to have at least a majority share.
A media and entertainment conglomerate, Liberty owns Starz, a digital pay-TV company, and the Atlanta Braves baseball team, and it holds shares in Barnes & Noble,
Once on the verge of bankruptcy, SiriusXM has become a cash machine in recent years. It posted a $427-million profit last year, up tenfold from 2010. Revenue of $3 billion was up 7% from 2010, thanks to a steadily growing number of subscribers. SiriusXM currently has 23 million customers who pay anywhere from $8 to $18 a month for access to its 140 specialty radio channels.
Liberty's executives have said they plan to combine SiriusXM with another property, likely its Starz pay-TV business, and spin the combined entity off as a separate company in order to avoid paying taxes for acquiring SiriusXM.
Eddy Hartenstein, publisher of the Los Angeles Times and chief executive of its parent,