ICAO
Here are the rules, I think you will find you answe from the applicable pragraphs of ICAO Annex 1.
2.1.10.1 A Contracting State, having issued pilot licences, shall not permit the holders thereof to act as pilot-in-command of an aircraft engaged in international commercial air transport operations if the licence holders have attained their 60th birthday or, in the case of operations with more than one pilot where the other pilot is younger than 60 years of age, their 65th birthday.
2.1.10.2 Recommendation.- A Contracting State, having issued pilot licences, should not permit the holders thereof to act as co-pilot of an aircraft engaged in international commercial air transport
operations if the licence holders have attained their 65th birthday.
Practical effects Article 33 of the Convention on International Civil Aviation (signed in Chicago, it is often quoted as the `Chicago Convention') limits the international recognition of flight crew licences to those who are in full compliance with the Standards of Annex 1 (note that paragraph 2.1.10.1 is a Standard). As a result, until 23 November 2006, even if an individual State authorizes a pilot-in-command (PIC) to fly in commercial air transport operations when over the age of 60 (65 from 23 November) that authorization can only be given for flights within that State's national airspace. This is because no State can force another State to accept its own deviation from an ICAO Standard. Article 33 does not apply to the co-pilot as paragraph 2.1.10.2 is a Recommendation, not a Standard. Articles 39 and 40 of the Convention are also relevant to the age limit of pilots-in-command engaged in commercial air transport operations as they authorize international flights by flight crew who do not meet all international licensing Standards, provided that an authorization is given by each State into which the aircraft is operated.
In practice, this means that if a pilot in command is under the age specified in paragraph 2.1.10.1 (60 years at present and 65 from November 2006) he cannot be prevented by reason of age from operating into any ICAO Contracting State. Further, once he has reached the specified age, he may still operate as PIC, subject to certain conditions:
1. his/her national Licensing Authority permits it; and,
2. operations are undertaken only in national airspace; unless,
3. another State has given specific authorization that such flights are permitted in its airspace.