Reports says the four-year deal will be worth £20million-a-year for United.
United chief executive David Gill said: “We are delighted to be entering such an important relationship with a company of the stature of Aon and to have its logo adorn our shirts from the start of the 2010/11 season.
“We look forward to being closely aligned with the world leader in risk management, a firm which shares our values and is an exciting partner for Manchester United. Today’s announcement clearly strengthens our position as one of the biggest clubs in world football.”
“It is a unique opportunity when two leaders in their respective fields can come together in a partnership such as the one we are announcing today,” added Greg Case, president and chief executive officer of Aon.
“Manchester United has one of the most recognised sports brands in the world. David and his team are all about winning and about excellence; the same holds true for the Aon team. We play to win in our business, and that is why we believe this partnership will create tremendous benefits for both organisations worldwide.
“While we are delighted that our brand will be showcased to over 330 million fans of Manchester United as well as the countless followers of football worldwide, we also are extremely excited about the opportunity to maximise the value of this partnership globally.”