TIAA-CREF and Norges Bank Investment Management (NBIM) are buying stakes in a US office property as part of a joint venture.

TIAA-CREF is taking a 50.1% stake in the Capitol Hill property, at 400-444 North Capital Street.

Last month, the two companies agreed a joint venture on another Washington property on 17th Street, with NBIM paying $196m (€154m) for a 49.9% stake.

The partnership’s latest deal sees the two companies split ownership of a 99-year ground lease, sold by US medical and benefits fund the MEBA Pension Plan.

The 609,000sqft asset is occupied by office tenants, as well as ground-floor retail, with 5% vacancy.

Suzan Amato, TIAA-CREF managing director of managed accounts and strategic joint ventures, said the property benefited from strong demand for space, with constrained supply of other office buildings in the immediate area.

As reported in July, NBIM and TIAA-CREF were in talks to invest $350m jointly in a San Francisco office asset.

NBIM was also in talks to buy the 1m sqft One Beacon Street building in Boston, expected to be sold for around $565m by Allianz Real Estate and Beacon Capital Partners.

In September, NBIM agreed to buy 45% stakes in three US office properties.

US REIT Boston Properties is selling the interests – in 601 Lexington Avenue and Atlantic Wharf, in New York City, and 100 Federal Street in Boston – for $1.5bn.