TORONTO, Cananda - Ontario Provincial Police Commissioner Chris Lewis is retiring from the force after a 35-year career.

Lewis, who joined the provincial police in 1978, will be stepping down on March 28.

He began his career as a provincial constable in Kapuskasing and rose through the ranks, becoming the OPP's deputy commissioner of field operations in 2007.

He was then appointed commissioner in August 2010, taking over for Julian Fantino, now a Conservative MP for the Toronto-area riding of Vaughan.

The provincial government announced Lewis's retirement Monday, saying he has served across the province in a variety of front-line, specialized and management positions.

It said Lewis is the first police officer to have been awarded all three levels of the Canadian Order of Merit of the Police Forces, presented by three successive Governors General.

A search for a replacement is beginning immediately.

"I want to thank Commissioner Lewis for a lifetime of outstanding service over his long and distinguished career. He should be proud of the significant contribution he has made to ensuring Ontario remains safe, strong and prosperous," Premier Kathleen Wynne said in a statement.

Under Lewis, provincial police launched a criminal probe into alleged financial irregularities at Ornge, Ontario's air ambulance service.

The commissioner was called in March to testify about the investigation before a legislative committee into the matter, and said it could take up to a year before charges, if any, are laid.

In January, Lewis took to YouTube to defend the force's response to the Idle No More protests, which some criticized as a failure to end rail blockages and other disruptions.

In the video, he said OPP guidelines for handling aboriginal incidents emphasize negotiation and minimal use of force.