Billionaire investor Warren Buffett’s Berkshire Hathaway (NYSE:BRK.A) has continued to buy shares in the broadcasting and radio company SiriusXM (NASDAQ:SIRI), adding more than 1.5M shares to push its stake above 32% this week.

Warren Buffett’s investment firm, Berkshire Hathaway, has increased its stake in Sirius XM Holdings to 32%. The company purchased roughly 3.6 million shares for about $87 million in separate transactions.

This followed Liberty Media's tracking stocks with SiriusXM in early September and a restructuring of Malone's media assets while also spinning out the Atlanta Braves a company in which Berkshire owns stakes.

SiriusXM shares rallied Monday after Warren Buffett’s Berkshire Hathaway raised its stake in the satellite radio company.

Warren Buffett's Berkshire Hathaway now has a stake of about 32.5% in Sirius XM’s publicly traded stock, having become the top holder last month.

Sirius XM, backed by Berkshire Hathaway, maintains strong market share and high ARPU despite competition from Spotify and Apple Music. Find out why SIRI stock is a Buy.