Elpida Memory Inc. bondholders failed Friday to persuade a U.S. judge to reconsider a ruling on the company's patent deals that could trouble their campaign to challenge the sale of Elpida to U.S. rival Micron Technology Inc. (MU).

Judge Christopher Sontchi declined to strike portions of his ruling that concluded Elpida's executives did not act in bad faith when they pledged some of the company's patents to Micron last year. Bondholders say the patent-licensing agreement gave Micron an unfair advantage in pushing through to completion its acquisition of the Japanese chipmaker and did little for the distressed Elpida.

At a hearing in U.S. Bankruptcy Court in Wilmington, Del., Judge Sontchi turned aside complaints from bondholders that they deserved a new hearing on the dispute. Bondholders said they weren't given access to all the information about the patent agreements between Elpida and Micron, which were linked to a sale of some patents to Rambus Inc. (RMBS).

Friday's ruling leaves standing findings by the U.S. judge that there was no collusion or improper purpose in the patent-licensing arrangements with Micron and that the patent deals were not designed to entrench Micron as the ultimate buyer of Elpida.

Judge Sontchi said even if he had dropped those findings from the ruling, as bondholders urged him to do, the ultimate decision validating the patent deals that tied Elpida to Micron would still stand.

Voting continues in Japan on Elpida's restructuring plan, which is based on the sale of the company to Micron for $2.5 billion. Bondholders have been laying the groundwork in U.S. bankruptcy court for a possible attack on the Micron sale, assuming it's voted though and approved by the court in Tokyo.

Japan is the main forum for Elpida's restructuring. The company placed its U.S. assets under the protection of a Chapter 15 bankruptcy case in Delaware for the duration. A manufacturer of dynamic random access memory, or DRAM, chips, Elpida lost ground in an increasingly competitive industry and resorted to the courts in an effort to lure a buyer that would fund a bailout.

Bondholders say the Micron deal significantly undervalues Elpida and offers an uncertain recovery over time to creditors. A court in Tokyo quashed a rival restructuring plan that was premised on a bondholder takeover, saying it lacked financing.