The move is the latest in a long-running legal wrangle over Eldorado, dating back to an original deal signed in 2017 but never finalized. Since then the two parties have been in dispute over the price of the deal and the right to conclude it.
In a statement issued late on Friday, Paper Excellence said Judge Renata Maciel had agreed with an arbitration panel that decided last year that the company, which owns 49.4% of Eldorado, may acquire the remaining stake to reach 100%.
It said the judge had decided the arbitration was correct in giving Paper Excellence the right to complete the acquisition and dismissed arguments to the contrary from Eldorado's majority owner, holding company J&F Investments.
The arbitration had mandated that the full deal be priced at 15 billion reais ($2.9 billion), as set forth in the original sale contract.
However J&F said it was "surprised" by the judge's decision because it had obtained a decision from an appeal court suspending the lower court proceedings.
In a statement, J&F - which also controls listed food processor JBS SA - said the latest court decision is "void" and ignores evidence regarding the arbitration proceeding.
Paper Excellence CEO in Brazil, Claudio Cotrim, said the Canadian company would consider a potential capacity expansion of Eldorado, based in the mid-western state of Mato Grosso do Sul.
Since the Eldorado acquisition, signed in 2017 but never finalized, Paper Excellence has acquired control of U.S. companies Resolute Forest Products and Domtar. In 2019 it bought Canada's Catalyst Paper.
($1 = 5.1724 reais)
(Reporting by Tatiana Bautzer; Editing by David Holmes)
By Tatiana Bautzer