The current age limit is an accord with ICAO at 65. There are limitations on this: you are required to pass a stress ECG every 2 years once over the age of 60, you have to fly 2 crew and the second crew member must be less than 60. The rule is the same for all - though if you work for an ICAO member state which has an age limit less than the ICAO recommended 65, I'm not sure how you'd do on a validation.