An investment fund run by the real estate firm Related Beal struck a New Year's Eve deal with Fidelity Investments to purchase five buildings in downtown Boston that once served as the business epicenter of the giant financial services firm.
The buildings, on a stretch of Devonshire and Congress streets near Post Office Square, contain 343,000 square feet of office and retail space spread across more than an acre of prime real estate known as the Block on Congress.
Financial terms of the deal were not disclosed.
Adam Banker, a spokesman for Fidelity, said the company put the block up for sale in March.
One of the buildings, at 82 Devonshire St., served as Fidelity's Boston headquarters from 1976 until the company moved to 245 Summer St. last year. At that time, Fidelity said it was considering leasing or selling its headquarters building and surrounding properties.
Fidelity has had offices in the buildings since the company was founded in 1946.
Banker said the space is still used as offices for about 500 Fidelity employees, some of whom will move to the new headquarters and an office in the World Trade Center next year. The company will continue to occupy some space in the downtown buildings until 2015. Fidelity has about 5,000 employees in Boston.
Stephen Faber, executive vice president of Related Beal, said it intends to "extensively renovate and reposition" 82 Devonshire and a building at 35 Congress St. and create "dynamic office space with 38,000 square feet of marquee, desirable retail space" available in late 2015 or early 2016.
The buildings were purchased by Related Real Estate Recovery Fund, which closed in January 2012 with $825 million in equity commitments. The fund has also invested in 100 Arlington St. and Lovejoy Wharf in Boston.
Taryn Luna can be reached at taryn.luna@globe.com.