http://www.icao.int/safety/Documents...port_FINAL.pdf
Upper Age Limit for Pilots
The current upper age limit for pilots engaged in international commercial air transport operations requiring two pilots, is 65 years. This limit applies to both pilots-in-command (PICs) and co-pilots, as a Standard for PICs and a Recommended Practice for co-pilots (Annex 1, paragraph 2.1.10). However, if one pilot is 60 years or more the other must be under 60 (colloquially known as the “one over one under” provision).
When the limit was increased in 2006 from 60 to 65 years, the ICAO Council and Air Navigation Commission (ANC) requested a review after five years of experience had been gained. A questionnaire was distributed to States and international organizations in 2012 and the results were considered by the ANC. This resulted in a new proposal which, if adopted, will permit two pilots aged 60-64 years to be simultaneously at the controls, and change the age limit for co-pilots from a Recommended Practice to a Standard. A State letter will be distributed in the first half of 2013 with a request for comments on the new proposal and if new provisions are agreed they could become applicable as early as November 2014.