Japanese investor Mitsui Fudosan is close to agreeing a joint venture with Grosvenor that will see it partner up on a large mixed-use West End development project.

Mitsui is in talks to take a 49% stake in Grosvenor’s £500M South Molton Triangle scheme, React News reported. It will invest £200M and Grosvenor will invest about the same, with further debt being added to the project.

South Molton Triangle is one of the largest developments in London’s most expensive district, comprising 204K SF of offices, 68K SF of retail and restaurants space, a 31-bedroom hotel and 33 homes.

It is a complex scheme, spread across 26 buildings, involving knocking some buildings down and retaining the façade, as well as some refurbishing listed buildings. But it is a prime location, with South Molton Street connecting Oxford Street and Bond Street tube station with Mayfair. The scheme is scheduled for completion in 2027.

The investment sees Mitsui extend its UK development pipeline further, while Grosvenor tweaks its own.

Mitsui teamed up with Dutch developer Edge earlier this year to buy the former home of the London Stock Exchange in Spitalfields, on which a 410K SF office scheme is planned.

Grosvenor recently sold its £1B build-to-rent development in Bermondsey to ADIA and Greystar. It has a development pipeline totalling £1B, including the South Molton Triangle scheme.