Fox offered no details on the case, but a lawyer for the employee said Beckel had "stormed out" of his office Tuesday when the man, who is a technician, came to do work on his computer, saying he was leaving because the worker was black.
Beckel, 68, is a veteran Democratic political strategist who is a regular on Fox's "The Five," where he discusses stories with four conservative panelists. The show recently moved into Fox's prime-time lineup with the firing of Bill O'Reilly.
Beckel had only returned to Fox in January. He'd been ousted in June 2015 while dealing with substance abuse, with then-Fox executive Bill Shine saying Fox "couldn't hold 'The Five' hostage to one man's personal issues." Beckel subsequently wrote a book "I Should Be Dead: My Life Surviving Politics, TV and Addiction."
Wigdor currently represents 22 clients with cases against Fox, including 15 involved in a lawsuit alleging racist behaviour by the network's since-fired controller, Judith Slater, who denies the charges.
Fox is involved in several legal cases involving O'Reilly and the late former network chairman Roger Ailes, who died on Thursday.
Wigdor's firm, in a statement, said that "we intend on holding (Fox News parent company) 21st Century Fox accountable for these actions and will be filing multiple other complaints in other matters next week."
Fox News fires Bob Beckel for racially insensitive remark