NBC, the US network TV company, is ditching its policy to air spirits advertising only three months after it said it would start taking such commercials. NBC broke a 54-year-old policy to shun spirits advertising when it agreed to take commercials from drinks giant Diageo for its Smirnoff Ice brand. But the decision has received considerable criticism from the word go and NBC said pressure from Congress, a strong backlash from advocacy groups and a lack of support from rival networks had caused it to review its policy.