Last year, John Malone bought Humewood Castle, a neo-Gothic jumble of towers, gables, and turrets at the foot of Ireland’s Wicklow mountains. The landscape of forest and heath could hardly be more different from Colorado’s high plains, where the cable cowboy owns thousands of acres -- but it reflects a broader strategic shift for Malone.

Over the past decade, the 72-year-old billionaire has amassed a European pay-TV empire that’s bigger than any cable operation he ever owned back home -- and he’s still buying.

In the 1980s, Malone won big with bets on startups like Discovery Communications Inc. and Black Entertainment Television and even by bailing out rival media tycoon Rupert Murdoch. But since largely abandoning the U.S. cable market in 1999, Malone has spent about $40 billion in Europe. His Liberty Global Inc. is on track to report 2013 sales of almost $15 billion, data compiled by Bloomberg show.

“The potential in Europe has been huge,” Malone said from his office in Englewood, Colorado. Malone in June moved Liberty Global’s tax home to London, but he still spends most of his time in the U.S.

Malone, whose family hails from the Cork region of Ireland, says he’s willing to take on debt to expand his European operations because he expects the cost of paying back loans to decline as economies improve and inflation rates rebound from crisis levels.

“A combination of cheap money and a gloomy view of the future gives rise to opportunity for those who aren’t quite so gloomy,” Malone said.

Europe has plenty of cable assets for Malone to corral, with thousands of providers across the 28-member European Union versus a handful in the U.S. And while more than 90 percent of Americans have pay-TV, only 41 percent of Europeans do, according to researcher Ovum Ltd., making the market ripe for bundled offers of Internet, phone, and programming.

“Malone coming in to Europe drives consolidation,” said Jeffrey Wlodarczak, an analyst at Pivotal Research Group in New York. He says the scale Liberty Global can achieve in Europe will allow Malone to invest in his cable systems and boost download speeds for consumers, though it may be difficult for him to raise prices because “the European market is pretty competitive.”

As he expands in Europe, Malone is running into headwinds, especially in Germany, a market Malone has long wanted to dominate. In June, he lost out to Vodafone Group Plc in bidding for Germany’s largest cable company, Kabel Deutschland Holding AG -- in part because he already had assets in the country and would have run into antitrust issues.

‘Good Partner’