Feb 1 (Reuters) - United Steelworkers members at BP's BP.L 440,000-barrel-per-day refinery in Whiting, Indiana agreed to a rolling 24-hour contract extension at the largest refinery in the U.S. Midwest, the company said in a statement on Sunday.

This would mean that the current collective bargaining agreement would automatically renew every 24 hours unless either the union or BP cancels the extension, according to BP's statement.