Research In Motion's two top executives have stepped down, amid growing pressure from investors over the firm's struggling BlackBerry brand.
Strong sales growth in the Middle East region was not enough to save Mike Lazaridis and Jim Balsillie, who resigned as co-chief executives of RIM, which makes BlackBerry smartphones.
Thorsten Heins, who joined the Canadian company in late 2007, took over as chief executive on Saturday, RIM said in a statement.
Both Lazaridis and Balsillie - who rank among RIM's largest shareholders - will remain at the company as board members, RIM said.
RIM's Nasdaq-traded shares have plummeted by 72.4 per cent over the past 12 months, hovering at eight-year lows.
The poor performance of the company led to calls by shareholders for a new leader of the firm, as well as intense speculation that RIM could be sold off.
The company has been hit by greater competition from Apple's iPhone and smartphones running on Google's Android operating system.
The BlackBerry brand was also hit by network breakdown last October, which affected users in the Middle East and several other regions.
Despite this, the company's performance in the Middle East and Africa has bucked the global trend. RIM claimed a 140 per cent increase in BlackBerry subscribers in the Middle East in the year up to August.
Patrick Spence, the company's managing director for global sales and regional marketing, said that 2011 was a "year of transition" for BlackBerry in the Middle East and Africa.
"In Saudi Arabia we are at over 225 per cent annual growth. We became the number one smart phone in Nigeria, and in South Africa we have 70 per cent of smartphone sales and the strongest brand in that country," he said.
"There are some things that have happened around the service interruption so it has been a year of mixed success - a year of transition," the executive added.
Mr Spence was speaking at a conference in Riyadh, prior to the announcement of the management changes at RIM.
He said the Middle East region was "incredibly important" for the company.
"If you combine the UAE and some of the growth we've now seen in Qatar and Lebanon it is incredible, so we are expecting this to be a big year," he said.
Mr Spence added that the company remained "extremely profitable", and did not need additional funds.
"Despite the challenges, we made a significant profit of $400 million last quarter, and we don't really have any debt on our balance sheet. We're in an excellent financial position, so we don't feel need to go out there to seek other funds," he said.