The Securities and Exchange Commission today charged a FleetBoston Financial Corp. unit with civil securities fraud involving improper mutual fund trading.

The SEC said the unit allowed certain investors to make rapid, market-timing trades in and out of its funds, in the latest charges brought under a wide-ranging probe of trading abuses among mutual funds.

In charges brought in U.S. District Court in Boston, the SEC said Columbia Management Advisors and Columbia Funds Distributor Inc. — both units of FleetBoston — allowed the market-timing practices.

From 1998 to 2003, the SEC said, Columbia Funds “entered into arrangements with at least nine companies and individuals allowing them to engage in frequent short-term trading in at least seven Columbia funds, including international funds and a fund aimed at young investors.”

SEC Enforcement Director Stephen Cutler said in a statement: “By putting their own financial interests ahead of their clients’ interests, this investment adviser and broker-dealer violated their most basic duties and violated the trust that mutual fund shareholders placed in them.”

The commission said its investigation of trading abuses in the US$7.4 trillion mutual fund industry was continuing.

The SEC said New York State Attorney General Eliot Spitzer was to bring a related action.