HUNDREDS of old public schools are lying vacant around the state - and many could soon be sold off by the Baillieu government to build more private schools.

In a move critics fear could exacerbate the drift to the private system, the government wants to offload some of the land to Catholic and independent schools, arguing it will improve schooling choices for students and parents.

The proposal is buried in an economic strategy released by Premier Ted Baillieu and Treasurer Kim Wells days before Christmas. It reveals that the Education Department ''currently holds in excess of 200'' vacant sites, some of which have been idle for years following mergers or closures.

''While some of these sites are in areas of declining numbers of school-aged children, others may offer potential for new schools,'' the strategy says.