It is quite unusual to announce any acquisition like this, let alone without financing. Most targets would require a commitment letter from banks that make financing more certain. Absent that, the target’s board would ask for at least a letter from the banks that states that the buyers were “highly confident” that financing would be obtained. These letters, invented by Michael Milken back in the 1980s for Drexel Burnham Lambert, are the realm of bidders who are unsure about financing. But at least the banks give some level of commitment in a highly confident level even if they can later back out.
A Deal for BlackBerry That's Not Yet a Deal - NYTimes.com