Originally Posted by jsloan

Based upon your spelling of 'labour,' I'm assuming this is the outbound part of a round-trip. You should be able to cancel for a credit, but the BE cancellation fee will be charged. If you wait until the flight has actually been cancelled, you can get a full refund -- not just a credit -- of the entire trip with no cancellation fee.

IMO, the only reason to cancel would be if your replacement trip would also be on UA and you were worried about getting one of the reservations canceled as a duplicate. If you're planning to fly AA or DL or Porter or Flair or whomever, I wouldn't cancel the AC/UA flight until it's absolutely necessary.