UPDATE 4-Liberty Global pays $3 bln cash for Unitymedia

* Europe's largest private-equity exit this year

* Deal values Unitymedia at 7.4 times 2010 EBITDA

* BC Partners makes 40 pct internal rate of return

* Liberty Global stock down 9 pct

(Adds share price, detail on ownership)

By Nicola Leske and Philipp Halstrick

FRANKFURT, Nov 13 (Reuters) - Liberty Global (LBTYA.O), the international cable operator controlled by John Malone, has agreed to buy Unitymedia from a private equity group for $3 billion in its first German acquisition.

The sale of Germany's second-biggest cable network by a shareholder group led by BC Partners [BCPRT.UL] and Apollo is worth $5.2 billion including assumed debt and marks the largest private equity exit in Europe this year.

The private equity group bought Unitymedia for 1.5 billion euros ($2.2 billion) in 2003.