The U.K. Financial Services Authority said Thursday that it has fined JPMorgan Chase & Co. about $48.85 million for failing to separate client money from the firm's, the largest fine in the FSA's history.

The regulator also warned firms that it has more such cases in the pipeline, urging them to ensure their internal controls over client money separation are in place.

The FSA said JPMorgan Securities Ltd. did not follow the rules by keeping client money held by its futures and options business separated from the firm's own money between November 2002 and July 2009. It said that during that period, the client money balance held by the business varied between $1.9 billion and $23 billion.

The error, which was discovered in July 2009, occurred following the merger between JPMorgan and Chase and was not deliberate, it said. Clients did not lose any money and the mistake did not result in any incorrect financial reporting, the FSA said.

A JPMorgan Chase spokesman in London would not comment.

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