Smartphone maker BlackBerry Ltd said it agreed in principle to be acquired by a consortium led by its biggest shareholder, Fairfax Financial Holdings Ltd, for $4.7 billion. Fairfax, led by Canadian investor Prem Watsa, owns 10 percent of BlackBerry. It has offered to pay $9 a share in cash for the Canadian company, which last week said it expected to report a quarterly loss of nearly $1 billion, along with far weaker sales than analysts had expected. Shares in BlackBerry had plunged since Friday, when the company warned of a sharp drop in revenue and massive job cuts. The group has until November 4 to conduct due diligence. The stock was trading up 27 cents at about $9 on Nasdaq after being halted earlier on Monday.