Manitoba MP Merv Tweed says he will resign his seat at the end of the month, leaving two Tory-held ridings in the province up for grabs.

Tweed -- who has served as MP for Brandon-Souris since 2004 -- made the announcement Monday, saying he was leaving politics to pursue opportunities in the private sector.

"I have had the honour to serve the public for many years at the municipal, provincial and federal level and my decision to leave politics was not made lightly," the 58-year-old said in a statement.

"Politics has been a major part of my life for many years and I will certainly miss its responsibilities and challenges."

Prior to being elected to the House of Commons, Tweed served three terms as a Progressive Conservative member of Manitoba's legislature. He's also been a municipal councillor and deputy reeve for the Rural Municipality of Brenda.

His resignation is effective Aug. 31.

With Tweed's resignation, a total of four Commons seats are currently empty.

Last month, Manitoba MP and former public safety minister Vic Toews gave up his seat, saying he was retiring from "public life" to focus on his family.

And former Liberal interim leader Bob Rae resigned his Toronto Centre seat in June, while Quebec Liberal MP Denis Coderre walked away from his riding of Bourassa to make a mayoral run in Montreal.