But the actress believes in taking competition in the right spirit.
Katrina, who has been endorsing Slice since 2008, considers both brands and their marketing "different".
"I think they are very different brands, and I see them as having different messages in terms of their marketing. Everything you do in the market will have opponents, that is why the competition is so high," the 28-year-old told IANS.
"Today, the consumer feels they deserve the best, and that's why there's so much advertising and marketing for each product. But at the end of the day, the choice is with the consumer," she added.
Katrina features in a new TV commercial for Slice. In an earlier commercial, she showcased her seductive side, in the new ad, which went on air Thursday, she has showcased her playful nature.
For the Frooti ad, Shah Rukh shot with kids, and according to Parle Agro, which is the parent brand, the commercial is an answer to brands which are "busy wooing viewers with seductive commercials".