US hedge fund ValueAct Capital, which has $16bn of funds under management, is scouring Japan for more investments, as some of the country’s biggest companies come under pressure from shareholders to boost profitability, according to people close to the fund.

The San Francisco-based hedge fund scored a major victory earlier this year when Robert Hale, one of its partners, won a position on the board of medical device and camera maker Olympus, in which it holds a stake of more than 5%. That marked the first time a US activist investor has been appointed as a director of a Japanese company.