City National Corp., the largest regional bank in Los Angeles, said Friday it agreed to acquire Independence Investment LLC, a Boston-based investment firm, from John Hancock Life Insurance Co. for an undisclosed sum.

Terms of the deal were not disclosed.

The acquisition of Independence, which manages $7.5 billion in U.S. equities on behalf of large institutional clients, will bring City National’s assets under management to nearly $27 billion. That excludes another $7 billion under management by companies in which City National holds minority interests.

Independence will be the largest asset manager affiliated with City National. The investment firm ranks as one of the largest managers of U.S. equities for institutions, pension funds and foundations, and has a team of top portfolio managers.

“This addition will significantly expand our outstanding asset management capabilities, particularly in the institutional market, where we see potential for additional growth,” Russell Goldsmith, the company’s chief executive, said in a statement.

The all-cash transaction is expected to close in the second quarter. City National expects the acquisition to be “modestly” accretive to earnings in 2006.

Shares of City National rose 0.3 percent to settle at $76.32 on Friday.