Oil refiner Eneos Holdings is considering selling as much as 70% of JX Advanced Metals in an initial share sale that may raise up to around ¥700 billion ($4.5 billion), according to people familiar with the matter.

The Eneos board is set to discuss the IPO at a meeting on Friday, with Chief Executive Officer Tomohide Miyata favoring a sale of 50.1% while others involved in the decision-making process prefer 70%, said the two people, who asked not to be named because the deliberations aren’t public.

There is a likelihood of Eneos settling on a number somewhere near the middle of the range, and there is no plan to issue new shares in JX, said the people. They added that the deliberations are ongoing, and details may still change.