LONDON (AP) — The chief executive of Primark, one of Europe’s biggest fast fashion retailers, has resigned after an investigation into his behavior toward a woman in a social environment.

Paul Marchant, Primark’s CEO since 2009, has apologized to the individual involved and resigned with immediate effect, the company said Monday. Shares in Primark’s parent, Associated British Foods, fell 4.9% in early trading, compared with a 0.8% drop in Britain’s benchmark stock index.

Marchant “acknowledged his error of judgement and accepts that his actions fell below the standards expected by the company,” Primark said in a statement.

The retailer has 451 stores in 17 countries across Europe and the U.S.

Eoin Tonge, finance director of Associated British Foods, has been name Primark’s interim CEO, ABF said in a statement.

The investigation was carried out by external lawyers and Marchant cooperated with the probe, Associated British Foods said. The company said it was committed to providing a “safe, respectful and inclusive” work environment.

“I am immensely disappointed,” ABF Chief Executive George Weston said in a statement. “We believe that high standards of integrity are essential. Acting responsibly is the only way to build and manage a business over the long term.”