The Ted Baker chief executive, Ray Kelvin, has resigned following allegations of inappropriate behaviour towards staff.

Kelvin, who started the company more than 30 years ago, took a voluntary leave of absence from his role in December after allegations of misconduct, including “forced hugs” and ear-kissing, were made against him.

The claims are being investigated by an internal independent committee, which commissioned the law firm Herbert Smith Freehills (HSF) to look into the allegations and the company’s policies, procedures and handling of human resource-related complaints.

Kelvin, 64, who has denied all allegations of misconduct, agreed to resign with immediate effect from his positions as the chief executive and a director of Ted Baker, the firm said.

The acting chief executive, Lindsay Page, has agreed to continue in the role, and the board has asked David Bernstein, who has chaired the firm since 2003, to act as executive chairman. The latter will stay in this role until at least 30 November 2020, by which time a new chairman will be appointed.

Kelvin, who founded the chain in Glasgow in 1988 and owns a 35% stake in the business worth more than £300m, had been criticised by former and current staff for alleged harassment at its head office. More than 300 former and current staff signed a petition on the campaigning site Organise complaining about his behaviour.

Details of the petition were first reported by the Guardian and in a statement about Kelvin’s resignation the campaigning group said: “After headline exposure in the Guardian, the campaign forced Ted Baker to launch a formal investigation into the allegations.”

Kelvin said in a statement: “Difficult though this decision is, given that Ted Baker has been my life and soul for over 30 years, I’ve decided that the right thing to do is to step away from Ted and allow the business to focus on being the outstanding brand it is so it can face 2019 with fresh energy and renewed spirit.”

As a shareholder, he said, he would support Page and be available to offer him and the team advice.

“I’m extremely proud of what we’ve achieved in building Ted Baker to the global brand it is today. Thank you to every single colleague, customer, supplier, and investor for your commitment to the business. We couldn’t have done it without you and I’m so grateful.”

He said the past few months had been deeply distressing and he would take time to consider his “next adventure”.

Ted Baker said the rest of the investigation would focus on its policies, procedures and handling of complaints. It expects HSF to finish its investigation by early April, and the main findings of its report are due to be published next month.

Kelvin, who owns nearly 35% of the fashion chain, will not receive any salary or benefits from Ted Baker following his resignation on Monday, and his 2016, 2017 and 2018 bonus share awards will lapse.

Bernstein said: “Ray Kelvin founded the business 32 years ago and has, together with the fantastic team around him, been the driving force behind it becoming the global brand it is today. As founder and chief executive, we are grateful for his tireless energy and vision. However, in light of the allegations made against him, Ray has decided that it is in the best interests of the company for him to resign so that the business can move forward under new leadership.

“As a board of directors, we are committed to ensuring that all employees feel respected and valued. We are determined to learn lessons from what has happened and from what our employees have told us and to ensure that, while the many positive and unique aspects of Ted’s culture are maintained, appropriate changes are made.”

Sharon Baylay is to act as the designated non-executive director for engagement with the workforce. The former BBC Worldwide and Microsoft executive, who joined the Ted Baker board last summer, was appointed to lead the investigation in December.

Shares in the FTSE 250-listed company fell by almost 5% in early trading, following news of Kelvin’s departure, but swiftly bounced back and were later up nearly 4% at 1973.5p. Last March they were changing hands at more than 3214p.

The retailer issued a profit warning last week after writing off £5m of unsold clothes.