Westinghouse was launching an expedited review application in the High Court in Johannesburg, it said in a statement.
Judge Thokozile Masipa was apparently appointed on September 17 to case-manage its review application.
The company said it would continue attempting to secure outstanding documents from Eskom in the meantime.
Westinghouse had initially wanted to take the power utility to court to get an interdict to stop it from either signing a contract with Areva or implementing the contract if it had already signed it.
It wanted Eskom to provide documents detailing how Areva had been awarded the R4bn tender to replace steam generators at the Koeberg nuclear power plant in Cape Town.
Eskom said the tender was awarded by its board tender committee on August 12, and that both Areva and Westinghouse were notified of the decision.
The High Court in Johannesburg ruled on September 5 that the power utility had five days to hand over tender documents.
“Based on documentation which Eskom has provided to date, Westinghouse maintains its stance that Eskom’s decision was flawed on various levels and should be set aside by the court,” it said.
The company alleged Eskom had failed to conduct a fair and transparent tender process.