Three senior traders who were previously suspended in connection with a global probe into the currency markets have been fired by their employers, according to people familiar with the matter.

Richard Usher, formerly chief currencies dealer at J.P. Morgan Chase & Co. in London, was placed on paid leave in October 2013, according to people familiar with the matter. Mr. Usher was fired by the bank in the first week of October, a person familiar with the matter said, and was listed as inactive on the register of approved individuals of the U.K. Financial Conduct Authority as of October 6.

Mr. Usher couldn't be reached for comment.

Earlier this month, HSBC Holdings PLC fired London-based senior traders Edward Pinto and Serge Sarramegna, both of whom were suspended in January in connection with the probe into currency markets, according to a person familiar with the matter. Mr. Pinto and Mr. Sarramegna couldn't be reached for comment.

The firings come as banks involved in the investigation into possible wrongdoing in the currency market move closer to reaching a settlement with the U.K.'s FCA, according to several people familiar with the matter.

The FCA started its probe in 2013. The investigation was initially focused on whether traders sought to manipulate foreign-exchange prices to their own advantage, but it has now expanded into many areas.

The Wall Street Journal reported last month that the FCA had held preliminary settlement talks with executives from Citigroup Inc., J.P. Morgan, Barclays Bank PLC, Royal Bank of Scotland Group PLC, UBS AG and HSBC.

People familiar with the matter say the settlements, which could be announced before the end of the year, are likely to see several banks fined for failing properly to supervise employees. The FCA declined to comment.

J.P. Morgan and Citigroup announced Tuesday they have boosted their legal expenses to about $1 billion for the third quarter, foreshadowing a possible settlement into far-reaching investigations into the inner workings of the vast foreign-exchange markets.

Katie Martin contributed to this article.

Write to Chiara Albanese at chiara.albanese@wsj.com

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