The Scot raced for Force India from 2011-13 after spending a season as reserve driver, scoring 121 points in 58 starts with a best finish of fourth.
"Nothing went wrong with Paul," said Mallya. "I like him, he is a great friend and hopefully he will remain that but every team needs to move on.
"We gave Paul a good stint with us, it wasn't just one year. We gave him the opportunity, he did a lot for us.
"If the British fans are disappointed I apologise, but such considerations don't really merit or drive the final choice.
"We felt, and all my team members felt, that new car, new challenges, perhaps a new driver line-up would also be appropriate."
DI RESTA UNLIKELY TO STAY IN F1
Di Resta's hopes of remaining in F1 are slim, although Sauber, Caterham and Marussia all still have drives available.
Mallya says he hopes the Scot can stay on even though the 27-year-old now appears unlikely to remain on the F1 grid, with a return to the DTM with Mercedes a possible alternative.
"He's a great guy, a good driver. I've nothing against him or Adrian for that matter, they both remain good friends.
"The bottom line is I wish he stays in F1, but don't forget I brought him to F1 from DTM and gave him that opportunity.
"So I hope he stays - who knows, sometime in the future there might be another opportunity."
Sutil remains a contender for a Sauber drive, although he is not certain of remaining in F1 either.