Washington ? The government awarded 70 percent of its contracts for Hurricane Katrina work without full competition, wasting hundreds of millions of taxpayer dollars in the process, says a House study released Thursday by Democrats.

The report, a comprehensive overview of government audits on Katrina contracting, found that out of $10.6 billion in contracts awarded after the storm last year, more than $7.4 billion were handed out with limited or no competitive bidding.

In addition, 19 contracts worth $8.75 billion were found to have wasted taxpayer money at least in part, costing taxpayers hundreds of millions of dollars, according to the report. It cited instances of double-billing by contractors and cases of trailers meant as emergency housing sitting empty in Arkansas.

Aaron Walker, a national spokesman for the Homeland Security Department’s Federal Emergency Management Agency, the primary agency for awarding hurricane contracts, said FEMA already was working to improve its contracting process based on “previously issued, nonpoliticized, reports.”

In their report, Democrats acknowledged that some no-bid contracts were necessary to provide quick aid in the immediate aftermath of the Aug. 29, 2005, storm. But they noted that while 51 percent of Katrina contracts awarded in September were limited or no-bid, that percentage increased to 93 percent in October.