Britain has cleared the way for Scandinavian Airlines System to buy a minority stake in British Caledonian Airlines but plans to ensure that the carrier will remain under British control. The possible merger with SAS has touched off powerful opposition in the British government. Britain's transport secretary said he would revoke British Caledonian's route licenses if an SAS deal meant foreign control. Recently privatized British Airways made an offer for British Caledonian but reduced it by more than one-third after the October stock market crash. SAS says it wants 40% ownership of the carrier but would settle for voting power of less than 30%. SAS has not disclosed a price, but industry sources believe the offer is between $91.5 million and $183 million.