Blatter, speaking at a news conference after the FIFA Congress when talks regarding age limits for senior officials were deferred for a year, was asked why there should be age limits for referees if he thought they were discriminatory against officials.
Top FIFA referees, often at the peak of their fitness and with years of valuable top level experience, currently have to retire at the age of 45.
Asked if this was just as discriminatory as forcing competent officials to stand down from FIFA when they reach a certain age, the 77-year-old Swiss replied: "You are absolutely right.
"The referees' committee has looked at this in recent years, but the moment has come for us to open this file again. We are missing (out on) the top referees and we have to have a look at this again."
Any change depends on recommendations by FIFA's referees committee, but Blatter has been highly critical of international refereeing standards in the past, especially after the 2006 World Cup finals in Germany.