Rakuten was planning to introduce free shipping on purchases at its online mall on orders over 3,980 yen ($36) from Mar. 18. Vendors have complained they are being forced to shoulder the shipping costs, undercutting margins.

The commission's recommendation is a blow to Rakuten CEO Hiroshi Mikitani's plans to take on rivals like Amazon. Rakuten was raided by the regulator earlier this month.

Rakuten was not immediately available to comment.

(Reporting by Sam Nussey; Editing by Shri Navaratnam)