Brown Brothers Harriman, a Boston-based global custodian, on Tuesday said that it expanded its relationship with OppenheimerFunds to provide middle and back office services through a new “lift-out” agreement.

The "lift-out" involves operations that handle $155 billion in assets across more than 350 domestic and offshore investment vehicles.

The new contract, effective on Tuesday, calls for BBH to establish a new servicing center in Centennial, Colo., where OppenheimerFunds’ current back-office operations are located. BBH will hire almost 200 OppenheimerFunds employees to man it. The new mandate will focus on middle office, accounting and administration for funds registered under the 1940 Investment Company Act.

BBH, which has $2.3 trillion in assets under custody, has provided OppenheimerFunds with global custody, cash management, foreign exchange and other securities services since 2007.

While it is common for investment funds to outsource some of their middle and back office operations to third party custodian banks and administators, a "lift-out" involving the hiring of staff is rarer. Other custodian banks such as BNY Mellon, State Street and Citi offer similar services.

“The combination of BBH’s industry-leading accounting system and Infomediary technology allows OppenheimerFunds to leverage a platform positioned for future growth,” says Darren Walsh, executive vice president of Oppenheimer Funds.

Walsh said that “OppenheimerFunds will benefit from BBH’s world-class infrastructure and scale and gain an exceptionally talented staff from OppenheimerFunds with the ability to operate a service center in the Mountain Time zone to further enhance its 24-hour global service model.”

Launched in 2002, BBH’s Infomediary platform is an outsourced post-trade communications system which allows fund managers to connect with the global financial messaging network operated by the Society for Worldwide Interbank Financial Telecommunications and other matching platforms such as one operated by Omgeo.