TOKYO, Aug 3 (Reuters) - U.S. investment bank Houlihan Lokey Inc said on Tuesday it will launch a tender offer to buy Tokyo-based mergers-and-acquisitions (M&A) advisory firm GCA Corp in a deal worth about $591 million to tap Japan's growing M&A market.

Houlihan Lokey, which has strengths in mid-cap M&A deals, will offer 1,380 yen ($12.63) a share in cash, a 31.3% premium to the stock's Monday closing price, to acquire all outstanding GCA shares.

"The acquisition of GCA will create one of the largest technology advisors in the world, one that more closely matches the size and importance of this sector in today's global economy," Houlihan Lokey Chief Executive Scott Beiser said in a statement.

Dealmaking is rising in Japan, driven by local conglomerates seeking to divest non-core assets or looking overseas for growth in response to the country's aging population.

GCA said in a separate statement its board has agreed to the tender offer. ($1 = 109.2800 yen) (Reporting by Makiko Yamazaki; Editing by Kim Coghill and Christopher Cushing)