(Reuters)—A unit of Citigroup (C.N) must pay $500,000 to a former branch manager who alleged the company fired him because of his age, according to a decision by a Financial Industry Regulatory Authority arbitration panel.

The ruling, made by FINRA on Jan. 25, found Citigroup Global Markets violated Florida's civil rights statute in 2008 when it terminated Edward Laurence Bowne, then a branch manager in Stuart, Fla.

Mr. Bowne, 66 at the time, joined Citigroup in 1997. He had more than 25 years of experience in the financial sector, according to a document filed in the case by his lawyer.

Winning a discrimination case against a brokerage is unusual, say lawyers. Claimants typically need strong proof that age was a major factor in the dismissal under Florida law. That usually includes blatant statements of age bias made by the employer, they say.

Mr. Bowne's employment situation began to deteriorate in 2004 when Citigroup hired a new regional manager who oversaw Mr. Bowne and other branch managers, according to the document. He began to hear from other branch managers who told him they were being "forced" back into broker positions and replaced with younger employees.

Mr. Bowne's manager made frequent remarks about age, according to the document. For example, he said that Mr. Bowne was "getting kind of long in the tooth" for the job, and "When you reach your age, you should think of retirement and not working," Mr. Bowne alleged.

The manager then engaged in a series of actions against Mr. Bowne. They included giving him a "final warning" for alleged employee complaints that Mr. Bowne said were unfounded, and reducing his bonus by 3% as a penalty for an alleged customer complaint, according to the document.

Mr. Bowne was eventually "offered" a position as a broker while on family leave after his sister died. Citigroup replaced him with a 42-year-old manager, according to the document. Mr. Bowne's experience was similar to other Citigroup managers in the region, he alleged.

The FINRA panel did not explain its reasons for the decision, as is customary in arbitration rulings.

The FINRA arbitration panel found that while Citigroup violated state law, it did not run afoul of a federal discrimination statute that Mr. Bowne also urged arbitrators to consider in the case. Proving age discrimination under federal law requires meeting a slightly different standard than under Florida state law, according to Mr. Bowne's lawyer, Cathleen Scott of Jupiter, Fla.

Under federal law, age must be the only factor in the dismissal.

"Citi complies with all age discrimination laws and is pleased that the arbitrators expressly found that Citi did not violate the federal age discrimination law," said Citigroup spokeswoman Elizabeth Fogarty. "We disagree with the decision regarding liability under the comparable Florida law and are reviewing our options."