Is it ok to use possession when referring to an entity, company or department.
For example: COMCAST's policy is .... vs. It is the policy of COMCAST to ........
It's a question of formality, as I think you guessed: 'the policy of COMCAST' is definitely more formal, and would be used in reports. But while it's less formal it's by no means (necessarily) informal to say 'COMCAST's policy'; this form might well appear in a company newsletter.