MEXICO CITY, Oct 5 (Reuters) - Mexico's Cemex said on Wednesday that it had appointed a new chairman and chief executive for its Latam subsidiary, after some former executives were fired amid investigations into improper payments relating to a land deal in Colombia.

Juan Pablo San Agustin was named chairman of the board of Cemex Latam Holdings, while Jaime Muguiro was named its new chief executive, Cemex said in a filing.

It also named Ricardo Naya as the director of Cemex Colombia.

Cemex said in September it had dismissed two senior executives and accepted the resignation of another after it found improper payments linked to a new cement plant in northern Colombia.

(Reporting by Jean Luis Arce; Editing by Vyas Mohan)