The former co-chief executive of Research in Motion ( now named BlackBerry ) has sold all his shares in the company, according to a new regulatory filing.

Jim Balsillie reported a zero-percent stake in the company he ran for more than 28 years, according to a 13G filing with the U.S. Securities and Exchange Commission, showing that he sold his 5.1 percent stake in the Canadian smartphone maker at some point in the last year.

While it's likely that Balsillie may have wanted to completely cut ties with the company that he co-founded following his resignation in January 2012, but it sends a strong perceived signal that he no longer has confidence in the company.

As a result $BBRY shares fell by more than 6 percent in pre-marking trading on the Nasdaq this morning after Bloomberg first reported the news, and at the time of writing was climbing back up but was still down in early morning trading.

Image: Google Finance

As a result, he has no voting rights on the company's board. It's not clear exactly when he dumped his entire stake in the company, but it happened at the latest of December 31, 2012, according to the filing.

One year ago, he owned 26.84 million shares. If he cashed in all his stock, he would have generated anything between a share price high of $17 per share or a low of $6.45 per share, equating to between $173.1 million and $456.2 million.

BlackBerry has tried to turn itself around in the last few months with the release of the BlackBerry Z10 only last month . But delays in getting the device to the U.S. market has concerned investors and shareholders. The keyboard enabled BlackBerry Q10 would arrive later in the year, leaving many loyal BlackBerry customers frustrated.

Shares in the company have taken a beating in the last couple of weeks since the launch, and fell by more than 25 percent following the launch.