(Reuters) - BlackBerry Ltd is abandoning a plan to sell itself and instead will replace its chief executive and raise about US$1 billion (S$1.24 billion) from institutional investors, including its largest shareholder, the smartphone maker said on Monday.

Shares of BlackBerry dropped 19 per cent to US$6.33 in pre-market trading. The company will raise the money with a private placement of convertible debentures.

BlackBerry's largest shareholder, Fairfax Financial Holdings, will take up US$250 million of the debentures.

Fairfax announced a tentative US$9-a-share offer for the Waterloo, Ontario-based company in late September. But Reuters said on Friday that Fairfax was struggling to finance the US$4.7 billion bid.