TOKYO (Reuters) -Swiss Bank UBS has re-hired Masazumi Toriyama to head its Japanese unit's global banking division, according to an internal memo seen by Reuters and confirmed by the company on Wednesday.

Toriyama, who previously spent 18 years at UBS, will start on August 4, replacing interim head Yasunori Saku, who will become chairman of Global Banking Japan, the memo said.

The moves are part of an ongoing expansion targeting a 50% increase in the division's headcount, a UBS spokesperson said.

UBS is the latest foreign bank to expand its investment banking offering in Japan as the return of inflation and corporate governance changes has spurred M&A deal-making among Japanese firms.

Earlier in July Citigroup Inc hired veteran investment banker Akira Kiyota from Nomura Holdings and promoted insider Taiji Nagasaka as co-heads of investment banking for Japan.

UBS's Global Banking Japan current chairman, Aki Nakagawa, will move to a general advisory role, while Masashi Oka, an independent director at Japanese technology firm NEC Corp, will join as senior adviser, the memo said.

(Reporting by Miho Uranaka; Writing by Anton Bridge;Editing by Chang-Ran Kim)