March 25 (Reuters) - Citigroup's Jan Metzger, co-head of investment banking for Asia, has stepped down, Bloomberg News reported on Wednesday, citing an internal memo.

Kaustubh Kulkarni, who was named co-head six months ago, will now be the sole head of investment banking for the region, the report added.

Citi did not immediately respond to a Reuters request for comment.

(Reporting by Fabiola Arámburo in Mexico City; Editing by Rashmi Aich)