May 22 (Reuters) - Traders of futures on U.S. short-term interest rates on Friday added to bets the Federal Reserve will deliver a policy rate hike as soon as October after Fed Governor Christopher Waller signaled he no longer felt the central bank should maintain an "easing bias" in its policy statement.

Pricing in the contracts now reflects about a two-in-three chance seen of a quarter-point interest-rate increase by the Fed's October meeting, and nearly even odds that a rate hike could come at the prior September meeting. Before Waller's remarks, traders were betting on a rate hike by December.