June 25 (Reuters) - Bank of America Corp"s (BAC.N) Merrill Lynch unit will pay nearly $11.7 million to resolve claims that it overcharged customers who invested in unit investment trusts, a U.S. regulator said on Friday. The payout includes a $3.25 million fine and $8.44 million of restitution, according to the Financial Industry Regulatory Authority. Merrill did not admit or deny wrongdoing in agreeing to settle. A unit investment trust, or UIT, lets people invest in a onetime public offering in a portfolio of securities, typically stocks and bonds. Unlike a mutual fund, a trust matures on a specific date, and pays investors the proceeds from securities it held. According to FINRA, Merrill failed to detect that between 2011 and 2015 its financial advisers sold $2.5 billion of their clients" UITs more than 100 days before the maturity dates, and used some or all proceeds to buy new UITs. It said the early rollovers may have caused more than 3,000 customers to incur sales charges they would have avoided had they held their UITs to maturity. Many newly purchased UITs used the same strategies as the UITs that were sold, it added. Bank of America spokesperson Alliccia Hernandez said Merrill addressed FINRA"s concerns by enhancing its supervisory system. Reporting by Jonathan Stempel in New York Our Standards: The Thomson Reuters Trust Principles.