A British regulator hit JPMorgan Chase with its biggest-ever fine -- $49 million -- for failing to follow rules for protecting clients' money.

    The U.K. Financial Services Authority said JPMorgan (JPM) failed to hold client money separately from the bank's, in a move that could have exposed customers to losses had the bank failed in the 2008 meltdown.

    The New York-based bank "committed a serious breach of our client money rules by failing to segregate billions of dollars of its clients' money for nearly seven years," Financial Services Authority enforcement director Margaret Cole said. "The penalty reflects the amount of client money involved in this breach."

    The FSA said J.P. Morgan Securities failed to segregate client money held by its futures and options business with JPMorgan Chase Bank. The amount of money that was put at risk by the bank's failures ranged from $1.9 billion in 2002 to $23 billion in the aftermath of the 2008 failure of Lehman Brothers.

    The segregation rule is important because it protects customers' money in the case of a bank failure, the FSA said. It added that it expects to bring more such cases.

    "This penalty sends out a strong message to firms of all sizes that they must ensure client money is segregated in accordance with FSA rules," Cole said. "Firms need to sit up and take notice of this action -- we have several more cases in the pipeline."

    The strength of the message was diluted a bit, however, by some complicating factors.

    The FSA said the fine was limited by the fact that no customers lost money. What's more, the regulator said, the bank promptly reported the error after discovering it and otherwise cooperated.

    This qualified JPMorgan Chase for a lower penalty than it might otherwise have paid.

    "The firm worked constructively with the FSA in the course of its investigation and agreed to settle at an early stage," the FSA said. "In doing so it qualified for a 30% discount."