BlackBerry Ltd. published an open letter to customers in major newspapers around the globe on Tuesday, reassuring them of continued service as changes are ahead. “You can continue to count on BlackBerry,” said the letter, also posted on the company’s website. “These are no doubt challenging times for us and we don’t underestimate the situation or ignore the challenges we are facing. We are making the difficult changes necessary to strengthen BlackBerry." The Wire Report reported this month that many of the company's roughly 70 million subscribers around the world are high-profile enterprise clientele in the health, government and finance sectors, who will be watching the company’s efforts to recover following a second-quarter loss of $965 million US. “Governments all over the world, global corporations and businesses that simply cannot compromise on security choose and trust BlackBerry. Security is our heritage, and the industry recognizes that BlackBerry is the most secure when it comes to the device, server and, of course, our global data network. Have no doubt that you can continue to trust us to keep your communication safe and private,” the letter said. Also on Tuesday, BlackBerry shareholders launched a class-action lawsuit in Quebec Superior Court, the Financial Post reported, charging that BlackBerry “knowingly or negligently misrepresented” the company’s financial position. BlackBerry said in September it is seeking a sale and plan to go private through a tentative offer from Toronto investment firm FairFax Financial Holdings Ltd. for $4.7 billion US. News reports have said other possible offers could come from New York-based private equity firm Cerberus Capital Management LP, BlackBerry founders Mike Lazaridis and Doug Fregin, Cisco Systems Inc., Google Inc., or SAP AG.