SYDNEY - Rio Tinto Group, the world's third-largest mining company, swung to a second-half loss, its first in four years, after taking an $8.9 billion one-time charge on the value of its aluminum business.

The loss was $1.76 billion in the six months ended on Dec 31, London-based Rio said on Thursday in an e-mailed statement. That compares with a record profit of $8.5 billion a year earlier. Deutsche Bank AG estimated on Monday that the company would take a charge of $6 billion on the unit.

The price of aluminum has declined 12 percent in the past year, hurting producers such as United Co Rusal and Alcoa Inc, which last month booked its first loss in two years. Rio Chief Executive Officer Tom Albanese said he won't take an annual bonus because of the charge related to the $38 billion acquisition in 2007 of Alcan Inc, the biggest mining takeover before the Glencore International PLC-Xstrata PLC combination proposed this week.