11Street Co., a South Korean e-commerce company, said Tuesday it has filed a complaint with the anti-trust regulator over its bigger rival Coupang, Inc.'s alleged unfair practices.

New York-listed Coupang has recently released the comparison between the maximum commission rates it receives from its product suppliers and competitors' rates to show its rates are lower than theirs.

The comparison comes after a local newspaper report that Coupang receives hefty commissions from its suppliers compared with its rival companies.

According to Coupang, 11Street's maximum commission rates reached 20 percent, followed by Shinsegae Group's online shopping malls Gmarket and Auction with 15 percent, and Coupang with 10.9 percent.

11Street has decided to bring the issue to the Korea Fair Trade Commission as such a "distorted" comparison could damage the company's brand reputation and affect its sales, an 11Street spokesperson said over the phone.

"Coupang released the comparison of maximum commission rates for just a couple of products with no specific standards or objective grounds. This clearly violates the local advertising laws as its comparison could mislead consumers," she said.

Of 11Street's 185 product categories, the commission rate of 20 percent only applies to three designer fashion categories, the spokesperson said.

In response, Coupang said the company finds no major problems as it made the comparison based on data from the companies' regulatory filings.

11Street expected it will take at least several months before the KFTC comes up with any rulings, such as a correction order or a fine. (Yonhap)