Kakao's headquarters in Pangyo, south of Seoul, Tuesday, a day before a planned strike by unionized members of the company. Yonhap

Unionized members at Kakao Corp. were set to stage its first walkout in the company's history Wednesday, demanding higher bonuses and profit sharing.

The walkout and a rally will take place near the messenger app operator's headquarters in Pangyo, south of Seoul, from 10 a.m. to 3 p.m. Around 600 members from five units of Kakao, including its headquarters, Kakao Pay and Kakao Enterprise, are expected to participate, according to industry insiders.

The move comes after the union and management failed to narrow differences in two rounds of wage talks mediated by the government last month.

Unionized members are reportedly demanding 13 to 14 percent of last year's operating profits as performance-based incentives. It is also seeking to redesign the compensation structure to include restricted stock units, a type of equity compensation, in the official bonus pool.