Elliott Investment Management is calling for Sumitomo Realty & Development to improve shareholder returns and corporate governance, saying the Japanese real estate developer’s stock is worth 40% more than its current value.

The New York-based investment firm released a public letter Monday, saying it would vote against Tokyo-based Sumitomo Realty’s senior management at the upcoming annual shareholders meeting if there’s no meaningful progress made on improving its value.

The letter is a rare public move by Elliott, which has kept quiet on most of its Japan investments. In the past year, news reports have unveiled the firm’s activist engagement with companies like Tokyo Gas, Mitsui Fudosan and SoftBank Group. Elliott’s stake in Sumitomo Realty was first reported in March.

Shares of Sumitomo Realty rose 0.7% to ¥5,540 on Monday in Tokyo. The stock has gained about 13% this year.

A Sumitomo Realty representative said in a statement that the company has had constructive discussions with Elliott on improving returns and corporate governance, and will continue to do so.

Citigroup analyst Masashi Miki said Sumitomo Realty has already made progress on addressing the demands raised by Elliott, including in its recently published midterm plan. Still, pressure for improvements in governance and shareholder returns is likely to keep building in the broader Japanese property sector, Miki wrote in a note to investors.

Elliott said Sumitomo Realty is one of the most undervalued real estate developers in Japan, assessing that its stock is worth at least ¥8,000, based on the valuation of its real estate holdings and peer companies. It called on the company to unwind its cross-shareholdings in companies such as Taisei and Obayashi, increase its shareholder payout ratio to 50% or more and set a return-on-equity target of at least 10%.

Elliott owned a 2.99% stake in Sumitomo Realty at the end of March, according to public filings from the company. In the letter, the investment fund said it has built up a more than 3% holding. In Japan, shareholders who have held 3% of a company for more than six months can call a special meeting.

Most of Elliott’s Japan investments have focused on boosting returns through share buybacks, selling off older real estate holdings and unwinding equity stakes in other companies. Sumitomo Realty’s annual shareholder meeting is scheduled for June 27.