A group of three U.S. companies filed a lawsuit seeking 114 million yen in damages against a Tokyo preparatory school operator Wednesday over alleged illegal copying of their computer software, lawyers for the companies said.

The three companies — Microsoft Corp., Apple Computer Inc. and Abode Systems Inc. — are also demanding LEC Tokyo Legalmind Co. erase software subject to the lawsuit.

According to the suit filed with the Tokyo District Court, LEC Tokyo Legalmind illegally copied at least 545 kinds of application software, whose copyrights belong to the plaintiffs, and used them to prepare texts and keep track of student records.

The U.S. companies filed the suit after failing to reach an out-of-court settlement with LEC Tokyo Legalmind.

While illegally copied software was found at LEC Tokyo Legalmind’s school in Shinjuku, Tokyo, the plaintiffs will increase the damages claim if other schools are found to have also used the software, the lawyers said.

As a program was used to nullify the software’s anticopying function, LEC Tokyo Legalmind must have systematically engaged in illegal copying, the lawyers added. LEC Tokyo Legalmind runs preparatory schools for bar examinations.

Katsuo Sorimachi, president of LEC Tokyo Legalmind, said his company is ready to fight the suit because it is formally authorized to use the software.

Referring to Microsoft, Sorimachi said that as one of the plaintiffs was recently judged to have violated a U.S. antimonopoly law, LEC Tokyo Legalmind hopes to correct the “irrationality” of the three firms’ action through the lawsuit.