"Since joining the organization in 2004, Michael has done an outstanding job," said John LeBoutillier, chairman of Tennis Canada's board of directors. "He has helped strengthen Tennis Canada and grow tennis in Canada with a clear focus on performance. His leadership will be sorely missed as well as his passion for the sport.
"On behalf of the board of Tennis Canada, I wish Michael well in his next challenge and thank him for his contribution.”
Downey's resignation is effective Dec. 31. He will begin serving as chief executive of the Lawn Tennis Association on Jan. 6.
"It has been nothing but an honour to lead Tennis Canada for nearly a decade," Downey said in a release. "I leave knowing that Canada is making great progress in becoming a world leading tennis nation. I am so proud of what we have done together with our partners to grow the sport across all disciplines in Canada.
"I depart with mixed feelings because Tennis Canada is a great organization comprised of great people including a best in class board of directors. I wish the organization and sport even greater success under a new leader. I will be cheering from the sidelines."
Tennis Canada hopes to have Downey's replacement in place by the end of the year. Downey will replace Roger Draper at the Lawn Tennis Association.
"This is a huge privilege for me, at a fantastic time for British tennis," Downey said in a statement on the LTA website. "We have a tremendous opportunity in front of us, and it is an honour to be able to lead the work of the LTA in getting more people playing tennis.”
Downey served as Tennis Canada president and CEO for nine years.
"We set out to recruit a CEO with true success in business, with exceptional leadership credentials and ideally with significant knowledge of tennis," said LTA chairman David Gregson. "Michael demonstrably fits the bill perfectly and was the unanimous choice of our recruitment panel.”