Updated

Spanish telephone company Telefonica says its net profit last year plunged 27.3 percent to €3.9 billion ($5.14 billion), driven lower by a series of write-offs.

Telefonica said Thursday that "extraordinary impacts" wiped €2.5 billion off its profit margin. Those included the adjustment of the value of stakes in Telecom Italia and Telefonica Ireland, and the consequences of Venezuela's currency devaluation.

Telefonica's total revenue last year fell by 0.8 percent, to €62.4 billion.

The company reported healthy growth in mobile data revenue, which was up 12.8 percent on 2011. In Latin America, which provided more than half the company's revenue in the fourth quarter, that item was up 5.5 percent.

Telefonica shares were up 2.55 percent at €10.05 on the Madrid stock exchange in early trading.