MONTREAL -- Cogeco Inc. says its radio subsidiary has sold its Metromedia advertising division to Bell Media, owner of Astral Out of Home.

Cogeco Metromedia specializes in the public transit sector, with traditional and digital ad placements in Montreal Metro stations, on city buses, commercial parking lots and other locations.

Cogeco declined to provide the sale price, but said it purchased the operations in 2011 for $41 million.

Richard Lachance, head of the radio group, said the advertising signage industry has undergone big changes in recent years with the arrival of major players. He pointed to Quebecor Media and Bell, which grew with the acquisition of Astral.

Consolidation in the so-called out-of-home advertising sector leaves little opportunity for future growth, he added in an interview.

While he said Cogeco Metromedia has been "positive and profitable," the company plans to focus on strengthening its radio segment.

Bell Media owns CTV Montreal