BRUSSELS (Reuters) - U.S. cable group Liberty Global (>> Liberty Global PLC) has increased its stake in Dutch cable operator Ziggo (>> ZIGGO) to 28.5 percent, the Dutch company said on Saturday.

Liberty, which also holds a controlling stake in Belgian cable operator Telenet (>> TELENET GROUP) and Ziggo's Dutch rival UPC, acquired its first 12.65 percent of Ziggo when Barclays (>> Barclays PLC) was left with shares it failed to place for previous owners Cinven and Warburg Pincus .

Liberty had subsequently increased its stake to 15 percent.

"The supervisory board and the board of management will continue to act in the best interests of its stakeholders in assessing steps made by Liberty Global while continuing to focus on executing Ziggo's strategy," the Dutch group said in a brief statement.

Ziggo's shares have fallen by some 10 percent since the group cut its profit outlook for 2013 on July 18.

Dutch law would require Liberty, Ziggo's biggest shareholder, to make a bid for all of Ziggo should it acquire a stake greater than 30 percent.

Ziggo was listed on the Amsterdam exchange in March 2012 by Cinven and Warburg Pincus, both private equity firms, which sold their final share in the company in April.

Warburg Pincus and Cinven initially invested in Multikabel in 2005 and then embarked on an expansion strategy, adding Casema and Essent Kabelcom in 2006 and @Home in 2007, after which the company was rebranded as Ziggo.

(Reporting by Robert-Jan Bartunek; Editing by David Holmes)

Stocks treated in this article : TELENET GROUP, Barclays PLC, ZIGGO, Liberty Global PLC