Kevin Feige, president of Marvel Studios, made the announcement, reported Ace Showbiz.
It was pretty much a given he would put in an appearance in the third 'Thor' film. By the end of 'Thor: The Dark World' he was able to take the form of King Odin and had persuaded Thor (Chris Hemsworth) to return to Earth and be with Jane Foster, played by Natalie Portman.
He will also play a part in 'Avengers: Infinity Part 1 and Part 2' because his sceptre has one of the Infinity Stones in it and once it is placed in the Infinity Gauntlet (bear with us....) it will set off havoc for the band of superheroes to deal with.