In a filing with the U.S. Securities and Exchange Commission, Aon Corporation said its decision to move its Chicago-based headquarters to London is at least partially motivated by taxes.

The document, filed among others with the SEC Friday morning, said relocating to London will significantly reduce the company’s global tax rate and allow it to remain competitive with other international firms.

Aon said in the document that the company will be able to increase “future cash flows through a significant reduction in our global effective tax rate, due primarily to changes in the geographical distribution of income.”

AON said the primary reasoning behind the move is to put the company closer to emerging markets in Asia and the Middle East and the world’s top insurance market Lloyd’s of London, according to a statement issued on the company’s website.

“This was really a strategic decision that really represents of the evolution of a company that does business in over 120 countries around the world,” said spokesman David Prosperi.

Chicago will remain headquarters of the Americas for Aon Corp., which employs approximately 6,000 people in the Chicago-area. The company said the move will not cause job loss in either the city or the U.S.

“While I am sorry to see the official headquarters move to London, Aon remains an outstanding corporate citizen in Chicago, and we look forward to their continued growth and investment in the City’s business landscape,” said Mayor Rahm Emanuel in statement.

“While this decision is an important step in our global growth strategy, we expect there will be minimal impact on colleagues and I want to emphasize that this move will not cause any loos of jobs,” said Aon CEO Greg Case said in a memo.

The company estimates it will transfer about 20 top executives to London. It plans to relocate 750 jobs to its downtown Chicago offices in the Aon Center. The company said it also hopes to create 1,000 jobs across the U.S.