Julie Edghill, 39, of Sevenoaks, Kent, had claimed that male dealers at the London office of Den Danske Bank had "ostracised and isolated" her and made suggestive remarks about her appearance.
But an industrial tribunal dismissed her claims as "unreasonable and vexatious" after a three-day hearing in Bury St Edmunds, Suffolk.
Mrs Edghill, who now works for another bank in London, was ordered to pay part of Den Danske Bank's legal costs. Lawyers estimated the total bill at more than pounds 50,000.
Christopher Ash, the tribunal chairman, said Mrs Edghill had come "nowhere near proving sex discrimination against the bank" and her claims that she was unfairly paid less than male dealers doing similar work were unacceptable.
"We are satisfied that they [the bank's employees] did not consciously or unconsciously seek to treat the applicant less favourably by reasons of her sex," said Mr Ash. "We are not satisfied that the applicant at any stage was ostracised, isolated or sent to Coventry by the other dealers."
He added: "The applicant has not succeeded nor indeed has got anywhere near establishing that she was discriminated against on the grounds of her sex."