(Recasts with details on strategy, operational results)
Feb 18 (Reuters) - Barrick Gold Corp said on Wednesday it will sell its Porgera mine in Papua New Guinea and its Cowal mine in Australia to help reduce net debt by at least $3 billion by year-end, giving investors a long-awaited glimpse into its strategy.
Barrick, the world's biggest gold producer, also said it was reducing the size of its Toronto head office by close to half from 260 positions in 2014 to 140 in 2015, so lowering its administration costs.
Describing its strategy as going "back to the future," Barrick said it was returning to its roots of being lean, nimble and entrepreneurial to an environment where operational heads had greater autonomy and responsibility.
The announcement, which included details on how 35 high-level employees will be compensated, is the most detailed glimpse yet into Barrick Executive Chairman John Thornton's plans for the company.
Investors and analysts have complained that Thornton, who took over from Barrick founder Peter Munk in April, has not made clear his plans for the miner.
In the past 10 months, several key positions at Barrick, including the chief executive and the miner's corporate development team, have been eliminated.
Other than through asset sales, Barrick will reduce its debt through the leaner, decentralized operating model and joint ventures or strategic partnerships.
Barrick also said it will defer, cancel or sell projects that do not return at least 15 percent on invested capital.
Earlier, Barrick reported better-than-expected adjusted earnings of $174 million, or 15 cents a share. Analysts expected 13.6 cents a share, according to Thomson Reuters I/B/E/S.
The company reported a net loss of $2.85 billion, or $2.45 a share, as it booked $2.8 billion in after-tax impairment charges related mostly to its Lumwana mine in Zambia and its Cerro Casale project in Chile.
Some $930 million of the impairment charge related to Lumwana, where Barrick plans to suspend operations following legislation that raises the royalty rate to a level the company says makes the mine uneconomic.
Another $778 million was related to Cerro Casale.
Looking ahead, Barrick said it expects to produce 6.2 million to 6.6 million ounces of gold in 2015 at all-in sustaining costs of between $860 and $895 per ounce.
In 2014, Barrick produced 6.25 million ounces of gold at all-in sustaining costs of $864 per ounce.
Barrick's in-the-ground gold reserves fell to 93 million ounces at end-2014 from 104.1 million a year ago. (Reporting by Nicole Mordant in Vancouver; Editing by Ken Wills and Lisa Shumaker)