(Adds context, response from involved parties)
By Gram Slattery
SAO PAULO, Nov 30 (Reuters) - A Brazilian bankruptcy judge overseeing Oi SA's in-court debt restructuring has put newly appointed Chief Executive Officer Eurico Teles in charge of negotiating with creditors, the telecom operator said in a filing.
The decision, disclosed late on Wednesday night, gives Teles powers to draft a debt restructuring plan and present it to the judge without board approval, a move that severely weakens the power of influential shareholder Nelson Tanure.
Preferred shares of Oi were down 1.3 percent at 3.88 reais ($1.19) in early trading.
The company and a spokesman for Tanure declined to comment.
According to the filing, Teles is the "person responsible for conducting and concluding negotiations" by Dec. 12, the new deadline for a proposal to restructure some 65 billion reais of debt in Latin America's biggest bankruptcy case ever.
In the last several months, the board and management have clashed over competing plans to take Oi, Brazil's fourth-largest carrier by users, out of bankruptcy.
The board, controlled by Tanure and his allies, has been pushing a plan with relatively little creditor support that would imply a 73 percent loss on the original value of some bonds, according to an analysis by Itaú BBA.
Meanwhile, management has been significantly closer to two major groups of private creditors who have been proposing a plan that would involve a much smaller haircut.
With Wednesday's court decision, a resolution to the bankruptcy at a Dec. 19 creditors meeting is more likely, as debtholders and the parties in charge of the company are now more closely aligned.
$1 = 3.26 reais Reporting by Gram Slattery; Editing by Lisa Von Ahn