The government and four highway operators are seeking payment of 6.7 billion yen in penalties by Sept. 29 from 38 contractors for allegedly rigging bids on bridge projects since 2003, government officials said Tuesday.

The breach of contract penalties -- the largest since the penalty system was introduced in June 2003 -- could reach 15 billion yen, including charges for unfinished projects and charges against other companies that are disputing the accusations, the officials said.

If other damages are included, the total amount sought from the contractors could reach 20 billion yen, they added.

The actions target Yokogawa Bridge Corp., Ishikawajima-Harima Heavy Industries Co., Kawasaki Heavy Industries Ltd. and other firms fined by the Fair Trade Commission,

As of Tuesday, the Land, Infrastructure and Transport Ministry was seeking 4.36 billion yen in penalties for 90 public works contracts.

The four highway operators created last October through the privatization of Japan Highway Public Corp. were seeking some 2.3 billion yen on 31 contracts, they said. The targeted companies have completed their subcontracted work.

The bid-rigging came to light in October 2004, after the FTC raided the offices of about 70 bridge builders. It imposed 12.9 billion yen in fines on 44 of the firms in March. Two have appealed.

Under the penalty system, the sponsors of public works projects can seek penalties of up to 10 percent of the value of the contract from contractors who violate the Antimonopoly Law by rigging bids, for example.

The penalty provisions were applied for the first time in June, when the land ministry sought 1.37 billion yen from six companies that rigged a bid to install information displays on roads.

In the latest case, trials are under way at the Tokyo High Court on 12 individuals and 26 corporations that have been indicted on criminal charges brought by the FTC.