Shares of BlackBerry developer Research in Motion slid again Monday trading despite replacing its co-founding CEOs, bringing in a new chairman and promising change.

RIM shares closed down 8.5 percent at $15.56, down $1.44, lowering the Waterloo, Ontario-based developer's market capitalization to only $8.15 billion, down $72 billion since 2008.

New CEO Thorsten Heins, in an investor call, declared we need to fight back and get stronger against rivals such as Apple and Samsung Electronics, whose smartphones have chomped away at RIM's once-dominant market share.

But the former Siemens Communications executive also said he would follow the roadmap of former co-CEOS Mike Lazaridis, who became vice chairman, and James Balsillie, who left management, adding he would abide by his predecessor's process discipline.

One innovation Heins, 54, cited was a willingness to consider licensing technologies and patents. That might be a means for RIM to capitalize on its intellectual property, a move called for previously by activist investor Victor Alboini, of Toronto's Jaguar Financial

Besides not generating sufficient profit, blowing introduction of the BlackBerry PlayBook that was supposed to do battle with Apple's iPad2, RIM last October experienced a three-day e-mail snafu that damaged its credibility with 75 million customers.

Replacing the founders with Heins and naming former Royal Bank executive Barbara Stymiest chairman is a positive sign, Alboini said in a Monday telephone interview.

It proves the company is finally listening to stockholders, he said. In September, Alboini's Toronto-based Jaguar Financial started buying into RIM. Later, Leon Cooperman's New York-based Omega Advisers joined, along with some other hedge funds and institutions.

If Heins doesn't execute in 18 months, he will be gone, Alboini predicted.

Alboini said he will give Heins a little time to act and Stymiest until the July annual meeting to show they mean business. But keeping both former CEOs Mike Laziridis and James Balsillie on the board, still means Heins won't be calling the shots, he said.

Alboini declined to say whether he had collaborated with Cooperman in the RIM coup. The company faced a deadline of Jan. 31 to report on management changes pushed by Canadian companies.

RIM will have to move quickly to restore market share lost to Apple and other smartphones running on Google's Android OS. BlackBerry products run on their own OS.

Moreover, the company has been delayed developing its new OS for the BlackBerry 7 phone after purchasing Texas-based QNX Software in 2010. It also has taken extensive charges on unsold PlayBooks over the past two fiscal quarters.

Other technology companies, including IBM, Apple and Texas Instruments, switched CEOs in times of crisis and near-bankruptcy and came roaring back. Others, like Eastman Kodak, filed for bankruptcy last week, while others, such as Wang Laboratories or WebVan, collapsed entirely.