MANILA, Philippines -- The House committee on public works and highways on Wednesday cleared three Filipino construction firms banned by the World Bank for alleged corruption.

After two hearings, committee chairman Southern Leyte Representative Roger Mercado said the inquiry had ended.

"Walang collusion, walang collusion [No collusion, no collusion]," he told reporters after the hearing, pointing out that no proof was presented during the hearings to back the World Bank?s charges against E.C. de Luna Corp, Cavite Ideal International Construction and Development Corp. and CM Pancho Construction Inc.

The three firms, along with four Chinese companies, were banned from participating in World Bank-funded projects after the international financial institution said it had ?uncovered evidence of a major cartel involving local and international firms bidding on contracts under Phase 1 of the Philippines? National Roads Improvement and Management Program, known as NRIMP 1.?

The banned firms allegedly colluded with government officials responsible for implementing the bidding process for NRIMP 1.

Mercado said they were ending the inquiry because the issue had been "completely ventilated," even if they were still waiting for documents subpoenaed from the Department of Public Works and Highways (DPWH).

No one from the World Bank attended Wednesday?s hearing.

At the hearing, Public Works Undersecretary Emmanuel Bonoan described the three banned Filipino firms as the "most reliable in the industry."

But Bayan Muna partylist Representative Teodoro Casiño said the DPWH was "in a state of denial" on the alleged collusion.

When asked by Casiño to discuss how contractors collude with each other to corner projects, Bonoan replied: "It's very difficult to make a guess how it is being done."

When pressed to tell the committee of the "telltale signs" of collusion, Bonoan said the only sure indication would be if only one handwriting was used on all the bids, the same letterheads were used, and the unit prices on all tenders were the same, down to the last centavo.

"Of course they won't do this; of course they won't use just one letterhead,? Casiño said. ?The contractors are not stupid. If this is the criteria you use in finding out if there's collusion, then I don't think you will find one."

But reading from a document on the bidding, Casiño noted the "high variances" between the winning bids and the rejected tenders.

"From the variance between the winning bidder and the other bidders, napakalayo sa biglang tingin, parang ang ibang bid eh talagang patalo [they are too far apart at first glance, it is like the other bids were intended to lose]," he said.