Interesting if you can extend the validity of all your points by flying with OW partners (when flight is both operated & marketed by them), the rules don't mention anything about it...
8.13 The kilometers earned by flying on LAN have a validity of 36 consecutive months, starting from the date of the flight. In all cases, the kilometers shall effectively expire on the last day of the month of said expiration.
8.14 The kilometers earned by flying oneworldŽ Airlines or Associated Airlines, or Partner Companies, using any services of the Partner Companies or promotional bonuses, are valid for 3 calendar years, which means that they shall expire on the 31st of December of the third year in which they were earned.
8.15 However, each time the passenger flies on LAN and earns 1 or more kilometers on the flight, all existing earned kilometers in his/her account up to the date of said flight will automatically be renewed, going on to have a period of 36 consecutive months, from the date of said flight and will effectively expire on the last day of the thirty-sixth month.