Citigroup Inc said there was no basis for rumors that it was responsible for a massive trading error that caused the markets to plunge on Thursday.

Citi had been conducting an investigation into the rumors on Thursday, but said on Friday morning that its investigation had determined that the rumors were false.

Based on our review, rumors about a trading error by Citi are unfounded. It is troubling that inaccurate and unfounded rumors were spread as far as they were, Citi spokeswoman Shannon Bell said in an email.

(Reporting by Maria Aspan, editing by Gerald E. McCormick)