The City Planning Commission unanimously approved a deal Monday to sell a Brooklyn Heights library branch and replace it with a high-rise.

If the City Council goes along, the 60,000-square-foot branch library would give way to a 36-story luxury tower with a new 21,500-square-foot library and 139 condos. The Brooklyn Public Library would get $52 million for its property.

Opponents argued several commissioners should have recused themselves because of potential conflicts. But City Planning chief Carl Weisbrod noted that the Conflicts of Interest Board reviewed those charges and found them without merit.