March 16 (Reuters) - United Steelworkers:
* Tentative agreement has been reached between bargaining teams for United Steelworkers (USW) Local 1976 and CP Rail
* United Steelworkers says details of agreement will not be made public until ratification votes are completed
* United Steelworkers says employees' existing collective agreement expires Dec. 31, 2017 Source text for Eikon: Further company coverage: CP.TO