Conservative Senator David Braley has resigned from the upper chamber, three years short of mandatory retirement.

Braley's office told CTV's Mercedes Stephenson that he has chosen to take an early retirement, citing frustrations and disappointment over the ongoing Senate expense scandal.

Braley's office gave a written statement dated Nov. 30 to the Governor General, advising of his resignation which was effective immediately. But the news didn't become public until today.

The 72-year-old businessman from Hamilton, Ont. is leaving the Senate after serving in the position for only three years. He would have been eligible to serve in the senate until he was 75.

He was appointed by Prime Minister Stephen Harper on May 20, 2010.

Braley had hinted at a possible retirement in September when speaking to a local Hamilton newspaper.

Braley told Hamilton Community News that his wife had asked him to consider retiring from the upper chamber. At the time, he said the reputation of the Senate was being tarnished.

In a statement issued Tuesday, Senate Government Leader Claude Carignan thanked Braley for his work in the upper chamber over the past three years.

"We respect his choice to spend more time with his wife and family, even if we wanted to rely on his thoughtful advice in the coming years," Carignan said.

"I want to acknowledge his generous contribution to Canada and his valuable work for Canadians during his three years in the Senate."

Braley -- president and owner of Orlick Industries Ltd. and a well-known philanthropist -- was the single biggest donor to Harper's 2004 Conservative party leadership campaign.

When he first joined the Senate, Braley told The Canadian Press his appointment was "a great, great honour," and provided an opportunity to make his community "a better place."

Braley currently owns two CFL teams: the Toronto Argonauts and B.C. Lions.