Pan-European entertainment conglom RTL Group is going Greek after agreeing to buy a majority stake in Alpha Media Group.

RTL, a subsidiary of German media giant Bertelsmann, has inked a deal with Alpha Media’s current owner, Dimitris Contominas, to acquire a 66.6% majority share in the Greek broadcasting company for E125.7 million ($185.5 million).

The No. 3 broadcasting company in Greece, Alpha Media comprises national channel Alpha TV, regional outlet Cosmos TV in Thessaloniki, radio stations Alpha 98.9 and Palmos 98.8, and Plus Prods., Alpha TV’s inhouse production company. The group generates annual revenue of about $150 million.

For the Luxembourg-based RTL, Greece offers a promising new market. The country’s net TV ad market grew from about $443 million in 2001 to some $750 million in 2007 and is projected to deliver annual growth of 6%-7% in the medium-term future.

Bertelsmann said last month it would consider cutting its stake in RTL from 90% to 75%, freeing RTL shares that could be used as acquisition coin.

With 44 TV channels and 32 radio stations in 10 countries, RTL is Europe’s leading broadcasting group.

“The acquisition of Alpha Media Group provides a unique opportunity to create value for viewers and advertisers in Greece as well as for our company,” said RTL chief exec Gerhard Zeiler. “Alpha Media Group already has a solid market position, and as the leading European entertainment network, we will contribute our expertise and experience to building a strong broadcasting company in an attractive market in close cooperation with our local co-shareholder Dimitris Contominas.”

Contominas will be named chairman of Alpha Media’s board of directors, while RTL will occupy five of the nine seats on the board and will have the right to nominate the company’s CEO and chief operating officer.

The deal remains subject to approval by the Greek Competition Commission and is expected to close in October or November.