Union Investment has joined the Ontario Municipal Employees Retirement Scheme (OMERS) in a London office joint venture.

Oxford Properties, the pension plan’s real estate arm, said Union took a 50% stake in its Watermark Place asset in the UK capital.

Union will hold the 50% interest for its open-ended UniImmo: Europa real estate fund.

Oxford said the introduction of a new partner was in line with its strategy to develop and grow partnerships with long-term strategic co-investors.

The asset has been refinanced with a new 10-year, £270m (€276.5m) debt facility from Pricoa Mortgage Capital. 

The 542,497 sq ft building, Oxford’s first investment in the London market in 2007, is fully let to Nomura on a long-term lease as its EMEA headquarters.

Oxford bought a 50% stake in what was then a development site, completed in 2009, before buying the building outright in late 2010.

The firm has also acquired offices in Paris in recent months, buying a Rue Blanche asset for €263m from The Carlyle Group and an Avenue de France building from GLL and Union.

At the time, Oxford chief executive Michel Vauclair said OMERS was looking to build a €1bn portfolio in Paris over the next 3-5 years, having invested more than €3bn in the UK.

In 2013, OMERS joined forces with The Crown Estate in a £320m central London development deal.