Update 1-Top official at Steel Partners Japan leaves firm

* Steel Partners Japan's top official O'Friel leaves firm

* Another senior official assumes O'Friel's responsibilities (Adds details)

By Junko Fujita

TOKYO, July 9 (Reuters) - The top official at Steel Partners Japan, Mark O'Friel, left the activist fund at the end of June, a month after it secured a rare victory at a Japanese shareholders meeting. O'Friel's responsibilities, which included building relationships with Japanese government authorities and the financial industry, will be taken over by Katsuyoshi Tanaka, another senior official at the firm, a Tokyo-based spokeswoman said.

O'Friel, who had worked at Morgan Stanley's (MS.N) Japan office, joined Steel Partners Japan last year after Yusuke Nishi, co-founder of the company, resigned last July.

O'Friel's departure came after Steel Partners toppled the board of wigmaker Aderans Holdings (8170.T) in a shareholder vote in May, a rare case where a foreign activist fund won support at a Japanese shareholders meeting.

Tanaka joined Steel Partners Japan in 2006 as a managing director after spending 18 years at trading house Mitsubishi Corp (8058.T). He negotiates with companies in which it invests, such as Aderans and brewery Sapporo Holdings (2501.T).

Tanaka earned a master's degree in business administration at Northwestern's Kellogg School of Management.

The company advises U.S. hedge fund Steel Partners LLC, which owns sizable stakes in more than a dozen Japanese companies and asks them to improve their management to increase shareholders' value. (Reporting by Junko Fujita; Editing by Elaine Lies)