NEW YORK (Bloomberg) ? JPMorgan Chase & Co., New York?s biggest lender, agreed to swap its corporate-trust unit for Bank of New York?s consumer and small-business bank in a transaction valued at about $3.1 billion.

JPMorgan will get 338 branches, mostly in the New York area, and $8 billion in business loans, the banks said in separate statements on Saturday. In return, Bank of New York will receive a business that services debt issues for companies and investors in 40 countries, as well as $150 million in cash.

The transaction would fulfil JPMorgan chief executive officer James Dimon?s vow to maintain his No. 1 ranking in New York, the wealthiest US banking market, as Bank of America Corp. and Wachovia Corp. encroach. The swap allows Bank of New York to exit a business where it has been losing deposits to bigger rivals and focus on asset servicing and private banking.

?Bank of New York has done a poor job managing the retail bank,? Prudential Equity Group Inc. analyst Mike Mayo wrote in a March 21 note to clients. ?The retail bank is an under-leveraged asset that has lacked focus and investments.?

Dimon, 50, has opened dozens of new branches, put automated teller machines in drugstores and doubled New York-based JPMorgan?s local marketing budget to fend off competition from rivals making acquisitions to expand in the region. With Bank of New York?s branches, he gets $15 billion in deposits and access to 600,000 households and 100,000 small-business customers.

Bank of America has rolled out more of its red-trimmed branches in New York since buying FleetBoston Financial Corp. for $48.3 billion in 2004.

Since then, Phildelphia?s Sovereign Bancorp Inc. and credit-card issuer Capital One Financial Corp. of McLean, Virginia, have agreed to acquire New York-area banks.