Prosecutors filed charges Monday against Michio Uchida, vice president of the Japan Highway Public Corp., for his involvement in rigging bids for bridge projects, resulting in inflated costs.

The charges were filed with the Tokyo High Court.

Uchida, 60, was arrested July 25 on suspicion of assisting in bid-rigging in violation of the Antimonopoly Law and causing unnecessary payments for Japan Highway in a breach of trust.

Investigators said a further probe found Uchida was more actively involved in the bid-rigging process than merely assisting. He was indicted for acting as a principal in conspiracy with others to rig bids for steel bridge projects financed by Japan Highway in fiscal 2003 and 2004.

Uchida's case marks the first time that those who placed orders for public works projects have been charged with criminal liability not as an assistant but as a principal in a conspiracy to violate the Antimonopoly Law. Usually the businesses involved in bid-rigging are subject to the law.

Uchida has denied allegations about involvement in bid-rigging and about causing damage to the highway builder and operator.

He was also charged with breach of trust for inflating construction costs by rearranging contracts among bridge builders for an elevated bridge in Fuji, Shizuoka Prefecture, for which orders were placed by the highway corporation in May 2004.

According to the breach of trust indictment, Uchida, knowing that former Japan Highway director Sozo Kanda, 70, was involved in arranging rigged bids among bridge builders, allegedly told Japan Highway officials to split the Fuji project into several orders, making it easier for Kanda to divvy them up.

Kanda was at that time an adviser to Yokogawa Bridge Corp. after retiring from Japan Highway, and thus was on the side of the contractors.

He has been charged with violating the Antimonopoly Law.