The American private equity owner confirmed it had started a "succession process" to prepare for McKay's retirement, but refused to comment on rumours it had already appointed headhunters.
"Frank is due to retire in October 2010," said Stuart Gent, an operating partner at Bain Capital, who sits on the Brakes board. "We are running a succession process to think about what we are going to do."
Bain, which acquired Brakes for an estimated £1.4bn in September 2007, denied rumours that McKay had already taken a back seat.
However, the timing of the announcement was described by one wholesaler as unusual.
"Not everyone retires at 65 and companies don't often admit this a year in advance," he said. "The word from suppliers is that Brakes is trading very well at the moment and that McKay has done a good job at stripping out costs from the business and adapting it for the recession."
Brakes' debt has risen to £1.5bn and there has been criticism that the wholesaler, which has a turnover of £2.047bn and made a pre-tax loss of £100m in the year to December 2008, is over-leveraged. However, McKay has always claimed he is "entirely comfortable" with the debt levels.
McKay, who has been at Brakes since December 2005, oversaw the Bain Capital buy-out and three subsequent acquisitions. In the past year, Brakes has acquired Woodward Foodservice, O'Kane Foodservice in Ireland and French foodservice business Rault.
Before joining Brakes, McKay was group CEO at builders merchant Travis Perkins, where he oversaw extensive growth and a quadrupling of the company's market cap. Before that, he was a board member of Blue Circle Industries and CEO of Blue Circle's heating division. He also held senior positions at technology manufacturer Rockwell International.