The executive offices at BlackBerry Ltd. are undergoing major changes as the smartphone maker announced Monday that chief operating officer Kristian Tear and chief marketing officer Frank Boulben are leaving.

Both joined the smartphone maker in mid-2012 in the buildup to the release of the new BlackBerry smartphones, which have seen sales fizzle.

BlackBerry spokeswoman Rebecca Freiburger confirmed that both of the executive positions will not be filled.

Also, chief financial officer Brian Bidulka will be replaced by James Yersh, who has been with the company since 2008, and board member Roger Martin has resigned.

The changes come as BlackBerry reworks its operations in an effort to reduce costs and downsize amid deepened financial losses.

The company has struggled to regain marketshare in the highly competitive smartphone industry where Apple's iPhone and a variety of devices on the Android operating system have taken the spotlight, and consumer interest, away from the once dominant company.

Both Tear and Boulben were tipped to be instrumental in the recovery of the BlackBerry name, with Tear being responsible for both operations and sales.

Boulben was behind the campaign for the new BlackBerry phones, which included a pricey 30-second spot during the SuperBowl and a series of other television spots that some critics complained undersold the smartphone's features.

Since the launch of the phones earlier this year, BlackBerry has seen its financial results erode, and in the second quarter booked a US$965-million loss mostly on poor sales of its BlackBerry Z10 touchscreen.

The company, based in Waterloo, Ont., is reducing its expenses to deal with the decline. It announced plans to lay off 40 per cent of its staff, or about 4,500 employees, and make changes in its executive ranks.

BlackBerry tried to sell its operations to other technology companies and investment firms. When that effort didn't generate a deal, it abandoned the plans earlier this month in favour of a US$1-billion financing deal led by Fairfax Financial (TSX:FFH) that gave the company a lifeline to turn around its operations.

BlackBerry hired John Chen as interim CEO and executive chairman to oversee the changes, taking over from ousted CEO Thorsten Heins.

"BlackBerry has a strong cash position and continues, by a significant margin, to be the top provider of trusted and secure mobile device management solutions to enterprise customers around the world," Chen said in a release.

"I will continue to align my senior management team and organizational structure, and refine the company's strategy to ensure we deliver the best devices, mobile security and device management."

BlackBerry will report its third quarter financial results on Dec. 20 when it's expected that Chen could flesh out further details on his plans to reshape the company.

Shares of the company were ahead 10 cents to $6.61 near midday on the Toronto Stock Exchange.