Exterior of office building The Westory Building in Washington, DC, which New York Life acquired in 2012, is among the office properties seeding the new JV.

NEW YORK CITY—New York Life Real Estate Investors and Finland’s Ilmarinen Mutual Pension Insurance Co. said Friday they had formed a joint venture to acquire core and core-plus office investments in major US markets. New York Life seeded the venture with a portfolio of initial investments, which Ilmarinen said is valued at about $620 million.