Original sentence: It has also been mentioned that once the Air India and Indian Airlines merger is complete, Flying Returns will remain the frequent flyers programme.Passengers that do fly with Air India on a frequent basis, can also fly with airlines that Air India has codeshare agreements with, and still recieve the same benefits
Edited sentence: It has also been mentioned once the Air India and Indian Airlines merger is complete, that Flying Returns will remain the frequent flyers programme.Passengers that do fly with Air India on a frequent base, can also fly with airlines that Air India has codeshare agreements with, and still recieve the same great benefits