The implementation of a new law to correct improper bidding processes has been lagging at the local level, the land ministry said Friday.

The ministry reported that only 60 percent of municipal governments have fulfilled their obligations to spell out their criteria for choosing bidders for public works under the designated bidding system.

Only selected qualified candidates can participate in the bidding process under the current system, which has been adopted for a large portion of public works.

The system has been criticized for making the bidding process opaque by allowing a public body to arbitrarily select a bidder.

While 93 percent of central government bodies and 94 percent of special state-backed corporations had disclosed their criteria for designating candidate bidders, only 59.9 percent of municipalities had done so as of March 31, a year after the law's enforcement.

The law was enacted in November 2000 at the initiative of Chikage Ogi, who became land minister after former minister Eiichi Nakao was arrested for allegedly taking bribes from a Tokyo construction firm.

The survey covered 19 central government bodies, 40 state-backed firms, 47 prefectural governments, 12 cities and 3,229 municipal offices.

The survey also revealed that 63 percent of the municipalities did not require bidders to submit details of their own cost estimates in the bidding.

Submission of cost estimates by each bidder is considered key to preventing bid-rigging because only serious competitors would spend the time and money needed to estimate the costs of construction.

The survey also showed that only 63 percent of municipalities require construction companies to submit details of multilevel subcontracts. These are considered key in preventing the practice of "maru-nage," or passing it all on, to gain unfair intermediate profits by merely subcontracting all the work to others.