NTT Docomo sold two plots of land in central Tokyo for about ¥59 billion ($371 million), according to people familiar with the matter, the latest large deal in Japan’s booming real estate market.

The mobile phone operator sold the land surrounding a building in Hitotsubashi, Chiyoda Ward, to Sumitomo for around ¥50 billion, land registry records show. It also sold land under a building in Shinjuku district to Japan Post Real Estate for about ¥9 billion. Docomo will continue to own the two buildings, said the people, asking not to be identified discussing confidential information.

An NTT Docomo spokesperson declined to comment on individual deals, but said in general that efforts to increase cost and asset-holding efficiency lead to more funding. A Japan Post Real Estate spokesperson declined to comment on the deals. Sumitomo representatives weren’t immediately available to comment.

Foreign and domestic investors including KKR and Blackstone have been flocking to Japan’s real estate market to buy properties that have been rising in price but are still seen by market players as having scope to gain. Docomo’s land sales come as the NTT subsidiary struggles to boost profits in its core consumer communications business that includes mobile phones.

Docomo’s operating profit decreased for a fourth straight year in the 12 months ended March 31, with the company citing heavy investment in equipment to improve communication quality and high promotional expenses.

People familiar with the matter said last year that NTT Docomo was considering selling the land on which four of its Tokyo office buildings are located, with a total price tag expected to exceed ¥100 billion. One of the buildings expected to be sold was NTT Docomo Yoyogi Building, an iconic skyscraper commonly known as Docomo Tower, but no deal for it has been completed according to land registry data. The latest two sales were completed by the end of March.