Sarah Tew/CNET

BlackBerry on Monday launched a new ad campaign to reassure its jittery customers that it's here to stay.

The Canadian smartphone maker, which has been struggling in recent months and recently reached a deal to go private, published an open letter to its customers and partners on social media and in 30 newspapers in nine countries, seeking to reassure them that it still has technology to attract users and that it will continue to exist.

"You can continue to count on BlackBerry," the letter said. "These are no doubt challenging times for us and we don't underestimate the situation or ignore the challenges. We are making the difficult changes necessary to strengthen BlackBerry."

The letter will appear in the papers, such as The Washington Post and The Wall Street Journal, on Tuesday, a BlackBerry spokesman told CNET. He said that it will also be posted to the company's Web site and distributed directly to BlackBerry's enterprise customers.

The letter comes as BlackBerry faces uncertainty about its future. The company has been rapidly losing market share in smartphones to Apple and Android. It also has seen more competition in its core business market, and its attempt at tablets -- the PlayBook -- flopped.

BlackBerry recently agreed to go private in a $4.7 billion dealled by Fairfax Financial Holdings. However, BlackBerry founder and former co-CEO Mike Lazaridis is considering another run with his old company, revealing in a regulatory filing last week that he boosted his stake in BlackBerry to consider an acquisition.

BlackBerry acknowledges in its open letter that it faces some tough changes, but says it remains committed to helping its customers. It argued that it has a "best in class productivity tool" in the launch of the BlackBerry 10 operating system and four new devices. BlackBerry also argued that it has "best in class security" and "best in class enterprise mobility management" that governments and other organizations rely on.

"Yes, there is a lot of competition out there, and we know that BlackBerry is not for everyone," the letter said. "That's OK. You have always known that BlackBerry is different, that BlackBerry can set you apart...You trust your BlackBerry to deliver your most important messages, so trust us when we deliver one of our own: You can continue to count on us."

Here's the full letter:

BlackBerry's open letter

Updated at 12:50 p.m. and 12:55 p.m. PT with additional details.