Photo courtesy of Certares

An investment partnership that completed a $171 million acquisition of the Hilton Boston Back Bay hotel plans a capital improvement program to modernize the 41-year-old property.

New York-based investment firm Certares, in partnership with Belcourt Capital Partners, bought the 390-room hotel at 40 Dalton St. and a 209-space parking garage this week.

“Boston is one of the only true ‘seven-day-a-week’ lodging markets in the U.S., with demand driven by a diverse set of corporate and leisure travelers,” Certares Director Mike Kusy said in a statement.

The seller, Ashforth Hospitality Trust, announced earlier this year the Back Bay property is one of six that it agreed to sell to reduce its debt by a combined $225 million.

The 25-story, 238,532-square-foot Back Bay hotel was developed in 1983 and acquired by Ashford in 2012.

Founded in 2012, Certares has $10.1 billion in assets under management focused on the travel and hospitality industries, including 12 hotels totaling more than 2,700 rooms.