South Korea's Samsung proposed an initial price range of $13.35 to $15.49 per share, representing a premium of 38 percent to 60 percent over BlackBerry's current trading price, the source said on Wednesday.
Representatives from the two companies, which are working with advisers, met last week to discuss a potential transaction, the source said, asking not to be identified because the conversations are private.
The Waterloo, Ontario-based company said in a statement that it "has not engaged in discussions with Samsung with respect to any possible offer to purchase BlackBerry. Shares of BlackBerry, which soared nearly 30 percent following the Reuters report, fell back about 15 percent in after-hours electronic trading following the statement.
Samsung also said in Seoul that it has no plans to acquire Blackberry. "Media reports of the acquisition are groundless," a company spokeswoman said.
Separately on Wednesday, Canadian newspaper Globe and Mail reported BlackBerry has shunned a handful of takeover overtures in recent months as its board and largest investor think its restructuring strategy will deliver greater shareholder value than current acquisition offers.
The board believes offering prices, some in excess of $7 billion, fall well below BlackBerry's potential asset value in the next few years, according to the Globe and Mail report.
BlackBerry, a one-time investor darling that pioneered smartphones, has regained some of its lost swagger under Chief Executive John Chen, who is leading a bid to regain market share it has lost to Apple Inc, Google Inc and Samsung.