Between January 1 and June 30, Anglo American suffered net losses of USD 3.015 billion (2.754 billion euros). In the same period in 2014, it gained USD 1.464 billion.
"The first six months of 2015 saw considerable further price decreases for our products amidst a volatile market environment and economic uncertainty in certain key markets," said chief executive Mark Cutifani.
"Having defined our portfolio and significantly improved operational performance, now is the right time to accelerate the right-sizing of the organisation that supports the future business.
This will include "those that will transfer with the businesses we are divesting," he added.
The Anglo-South African firm has made a string of costly writedowns on the value of its Brazilian Minas-Rio iron ore project.
It recorded a writedown of USD 3.5 billion due to weak mineral prices, including USD 2.9 billion on its Minas-Rio operations, and USD 600 million mostly linked to its coal mining in Australia and Canada.