The Scot, who was also being lauded for his contribution to the city, took charge at Old Trafford on November 6, 1986.
"I think it's always nice to be appreciated and recognised, and getting this recognition is testimony to all the hard work that has gone on at Manchester United in the last 25 years, not just by me, but by everyone at the club," he told the audience.
The 69-year-old, who celebrates his 70th birthday on New Year's Eve, also revealed that he has no intention of retiring just yet.
"I just don't think about retirement anymore," he added. "When you've been on the treadmill for so long, 25 years in my case, and my health is good at the moment, it's just a matter of looking forward to being the manager of Manchester United, rather than worrying about Alex Ferguson.
"I am enjoying it at the moment. We've got a good young team and a lot of youth at the club as well as some tremendous staff, so the future is good and I can keep enjoying it."
United travel to Liverpool in the Premier League on Saturday.