SEOUL (Reuters) - South Korea's POSCO (005490.KS: Quote, Profile, Research), the world's No.4 steelmaker, said on Thursday it had named its former chief operating officer to replace outgoing chief executive Lee Ku-taek.

Chung Joon-yang joined POSCO in 1975 and moved to POSCO Engineering and Construction in December 2008 to become the chief executive of the construction unit.

Chung will formally assume the top job after POSCO holds an annual shareholders meeting on February 27.

(Reporting by Miyoung Kim; Editing by Ben Tan)