Green received the charge on Wednesday after it was revealed that the businessman had used a derogatory term in a recent newspaper interview when talking about an associate.
"I apologise unreservedly if any offence has been taken by my remark," the 59-year-old told the club's official website. "I was actually trying to make the point, albeit clumsily, that I am not a racist.
"Imran Ahmad is a close friend and business associate and I would certainly have no cause or wish to offend him."
Green has been ordered to respond to the charge by next Wednesday.