Sumitomo Trust & Banking Co. said Monday it and a unit of French insurance firm Axa have agreed to establish an investment fund targeting the Japanese real estate market.

The fund to be set up by Sumitomo Trust and Axa Real Estate Investment Managers will focus mainly on investing in office buildings in Tokyo's 23 wards.

The two firms will work out the details of the investment fund by year's end, with an eye to raising approximately ¥50 billion in equity, Sumitomo Trust said.

The Japanese real estate market has remained stagnant since last year's collapse of U.S. investment bank Lehman Brothers Holdings Inc., but according to Sumitomo Trust, some major investors have shown signs of interest in resuming or starting medium- to long-term investment in high-end properties.