The industry ministry has suspended four of the nation's biggest construction companies from bidding for public works projects ordered by the ministry for four months following their indictment for alleged bid-rigging on maglev train projects.

Obayashi Corp., Kajima Corp., Shimizu Corp., and Taisei Corp. have been immediately barred from tenders for the Ministry of Economy, Trade, and Industry and its bureaus across the country through Aug. 5, it said Friday. The firms won't receive subsidies from the ministry over that time frame.

The four contractors have already been suspended from bidding for projects ordered by the Ministry of Land, Infrastructure, Transport and Tourism, and the Environment Ministry over their alleged collusion to select contract winners in advance.

On March 23, prosecutors pressed charges against the four companies and two individuals from Kajima and Taisei after the Japan Fair Trade Commission filed a criminal complaint against them over the Tokyo-Osaka maglev train line project.