Clattenburg had been accused by Chelsea of making a racist remark to John Obi Mikel during a game with United at Stamford Bridge last month. Chelsea are understood to be resisting calls for an unreserved apology to Clattenburg who has not officiated since the allegation was made.
The Football Association announced it was taking no action on Thursday and Ferguson, who spoke up for Clattenburg in the immediate aftermath of the allegation, said: "I did not believe it anyway. The unfortunate thing for Mark is that he has had to carry that stain for the last few weeks. Everyone in the game is pleased for him now - apart from Chelsea."
Former Premier League referee Graham Poll does not see a reason why Clattenburg will not be able to oversee a Chelsea game again in the future.
Poll himself was subjected to accusations from some of the London club's players in 2006, with allegations he had promised to "sort them out" later withdrawn.
"I don't think, given time, we will have a situation where Mark Clattenburg can't referee Chelsea," he told talkSPORT.
"Mark won't have a problem with the players at all. They truly believed Ramires had heard something improper from the start. You can understand the strong feeling, and the fact that it was misinterpreted is not the problem."
Poll went on to follow referees' union boss Alan Leighton in blaming Chelsea for making the allegation known, adding: "The issue is Chelsea football club. I understand they have to investigate the allegation and protect their employee.
"But they went so public and were so damming before they had looked at it first. That's the issue."
Source: PA
Source: PA