SEOUL, Sept. 21 (Yonhap) -- Fin.K.L, one of the late 1990s' most influential K-pop acts, is set to resume full-group activities for the first time in 21 years, the group's agency said Monday.

Gemstone E&M announced that all four original members -- Lee Hyo-ri, Ock Joo-hyun, Lee Jin and Sung Yu-ri -- have reunited under the Fin.K.L name and that preparations are underway for group activities.

"This time, it is a new start for activities as Fin.K.L beyond a one-off reunion," the agency said in a news release.

The quartet last performed together as a full group in 2005 with the digital single "Forever Fin.K.L." Although the members briefly reunited in 2019 for the JTBC variety show "Camping Club," releasing a new song tied to the show, that effort was viewed as a project linked to the program rather than a resumption of full group activities.

Debuting in 1998, Fin.K.L helped define the early K-pop girl group era with hits including "Blue Rain," "To My Boyfriend" and "Eternal Love."

Girl group Fin.K.L is seen in this photo provided by JTBC. (PHOTO NOT FOR SALE) (Yonhap)