Google is set to require all app developers on its Play store use its billing system, which takes a 30 pervcent cut for user purchases of digital goods, from October. 

The move has drawn opposition from app developers that have circumvented Google's fee by using other payment systems. 

Amid mounting criticism, the tech giant has decided to reduce its commission by half to 15 percent for the first $1 million of revenue a developer earns per year starting July 1. 

The Korea Internet Corporations Association, which represents major local tech companies, such as top portal operator Naver and messenger operator Kakao said Google's latest move still undermines fair competition as it forces developers to use the company's billing system, reports Yonhap news agency. 

"Google's fee reduction, which ignores the essence of the issue, is a temporary remedy," the association said in a joint statement with nine other financial and civic groups. 

"The National Assembly should restore fair competition in the mobile environment through revisions to the Telecommunications Business Act." 

Last year, lawmakers proposed bills that would ban app market operators from enforcing certain payment methods in mobile content transactions amid growing complaints from local app developers. 

Google has said that its service fee is used to reinvest in its platform and that its latest move will lead to a 50 percent reduction in fees for 99 percent of developers globally. 

Google's decision follows moves by rival Apple, which lowered its App Store's commission by half for developers that earn up to $1 million annually from the start of this year.