The 20-year-old's chances of gaining regular starting action at Old Trafford appeared to be limited, which brought about reported interest from a host of Championship clubs.
However, Powell has admitted that he was eager to prove himself in the Premier League and, as a result, he was determined to force through the switch to the King Power Stadium.
"I was on to my agent all day and he is probably sick of my voice, but I am glad it is done," Powell told the Leicester Mercury. "I tried to push it through with my agent because I wanted regular football, to be more involved in the Premier League, and we thought we would get a better opportunity here.
"I am here to get some experience and improve. I could have gone into the Championship and played week in and week out, but the Premier League is the next step and Leicester have given me that opportunity. I have to earn my place in the team first because it isn't given to you. That is the first step."
Powell could make his Leicester debut against Stoke City on Saturday afternoon.