Boston-based State Street Global Advisors (SSgA) will buy Bank of Ireland Asset Management for about $79.3 million, State Street confirmed on Friday.

The sale price includes BIAM’s estimated net assets of E14 million; the unit has about E26 billion in assets under management. About 120 of Bank of Ireland’s staffers will be transferred to SSgA once the deal is completed in the first quarter of 2011. State Street has more than 2,000 employees in Dublin, Kilkenny, Naas and Drogheda and is considered one of Ireland’s largest fund administrators.

The transaction has been in the works for several months as part of the Bank of Ireland’s restructuring plan, approved by the European Commission in July. State Street had also signaled in August that it wanted to expand its reach into more lucrative actively managed investments through acquisitions. State Street, considered the second biggest U.S. provider of index-based investments after New York-based Blackrock, has managed Bank of Ireland Asset Management’s passive investment funds since 2001. BIAM has about 500 clients, mostly Irish institutions and invests most of its assets in equities.

“The acquisition enables SSgA to expand its range of investment capabilities to include active fundamental management,” Scott Powers, president and chief executive officer of State Street Global Advisors, said in a statement issued Friday. “As our clients look for more solutions-driven investment strategies that span the risk spectrum, the addition of this team and capabilities will enhance our ability to deliver on those needs.”

The BIAM takeover is the latest in State Street’s acquisition trail. It recently bought Mourant International Finance Administration, a Channel Islands-based service provider for alternative investment funds and the securities services business of Italy’s largest retail bank, Sanpaolo SpA.