Sumitomo Realty & Development, the Japanese developer facing pressure from Elliott Investment Management to boost its value, is seeking to sell a group of office properties in Tokyo for at least ?100 billion ($700 million), according to people with knowledge of the matter.

The developer has earmarked 19 midsize office buildings for the divestment. It has asked real estate investment firms and agencies to estimate the value of the offices, which it is considering selling separately, the people said, asking not to be identified because the matter is private. It is also weighing the sale of eight rental apartment buildings in the city, they said.

Shares of Sumitomo Realty jumped as much as 6% and closed 2.4% higher at ?5,838 in Tokyo on Thursday.

Sumitomo Realty said in a statement that it is not true that it is considering selling the 19 office buildings. The company also said it plans to reduce nonprime assets to improve asset efficiency in line with its midterm business plan.

After taking a stake in Sumitomo Realty, Elliott said this week that the Tokyo-based company should do more to improve shareholder returns and corporate governance. The sale plans mark a shift from its business model of developing properties in-house, holding them for the long term, and earning steady income from tenants, toward a strategy targeting capital gains.

In a rare public letter, Elliott said it would vote against Sumitomo Realty¡¯s senior management at an annual shareholder meeting on June 27 if no meaningful progress is made on improving its value.

Elliott said the company 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 developer to unwind its cross-shareholdings, increase its shareholder payout ratio to 50% or more and target a return on equity of at least 10%.

Elliott has built up more than a 3% holding in the company, according to the letter.