HARRISBURG — Pennsylvania government agencies may not release people’s home addresses under the Right-to-Know Law without first making them aware their addresses have been requested and giving them a chance to fight it, a state court ruled Tuesday.

A divided Commonwealth Court came down in favor of the state’s largest teachers union and against the Office of Open Records in a decision critics say could make it more difficult to access information far beyond the addresses of school employees involved in the case.

The case was prompted by requests for the names and addresses of all school employees from school districts soon after a new version of the open records law took effect in early 2009.