OSLO, June 27 (Reuters) - Around 1,000 Norwegian oil service workers were locked out on Saturday morning after employers followed through on a previously announced escalation that is expected to disrupt drilling on the Norwegian continental shelf and some production.

The lockout was declared in response to an ongoing strike by several hundred members of the Safe union and will affect companies including SLB SLB.N, Halliburton HAL.N, Subsea 7 SUB.OL, DOF Subsea, Weatherford, DeepOcean and Baker Huges BKR.O, an industry group Offshore Norway said on Friday.