LONDON, June 6 (Reuters) - West Ham United ⁠co-chairman David Sullivan resigned from his position with immediate effect on Saturday after becoming aware of ⁠what he called "factually incorrect and entirely false, decades-old allegations" about to be published.

The 77-year-old ‌businessman also stepped down as a director of WH Holding Limited and West Ham, who were relegated from the Premier League on the final day of the season.

In a lengthy personal statement, Sullivan said he had become aware that the "factually incorrect and entirely ​false, decades-old allegations" concerning his personal life were due to be ⁠broadcast and published.

"The false allegations levelled against ⁠me have been sensationalised by the media," Sullivan said.

"After a lifetime spent building businesses in the adult ⁠industry ‌in which I have met thousands of women, it is sadly inevitable that a small number of improper conduct claims are being made against me.

"I categorically deny these claims."

Sullivan also declared that ⁠he would be suing the BBC for libel, along with any ​other media outlet that "repeats any ‌libelous allegations."

Reuters has contacted the BBC for comment.

ALLEGATIONS UNRELATED TO WEST HAM

The club said none of ⁠the allegations relate ​to West Ham or any of its operations.

"Interim Chief Executive Officer Karim Virani, reporting into the current Board of Directors, will continue to be responsible for leading the club's day-to-day operations," West Ham said.

"The club will provide an update ⁠on the future structure of the Board of Directors in ​due course."

Sullivan described his decision to step down as "incredibly painful" but one that was required.

"None of these allegations relate to my more than 30 years in football; West Ham United has been one of the greatest passions ⁠and privileges of my life," Sullivan added.

"I care deeply about the club, its supporters, its players, its staff, and its future.

"At what is already a challenging and important time for the club, I refuse to allow personal matters concerning me to become an unnecessary distraction or a source of instability."

Following their relegation, West ​Ham will play in the second-tier Championship for the first time since ⁠the 2011-12 season.

"I am stepping down to apply my full energy and attention on fighting these false allegations," ​Sullivan said.

"I have officially engaged my legal team and we are ‌preparing to issue legal proceedings in respect of each ​and every false complaint that has been made against me.

"I will be seeking full redress, legally and publicly, on every single front."

(Reporting by Rohith Nair in Bengaluru; Editing by Ken Ferris)