* South32 takes big impairments on manganese, coal
* Leads to $1.7 bln half-yr loss (Adds details, share price)
SYDNEY, Feb 25 (Reuters) - Australia's South32 Ltd S32.AX on Thursday reported a first-half loss of $1.7 billion, hurt by big writedowns for its manganese and energy coal businesses.
South32 is the dominant global producer of manganese, and has interests in alumina, silver, nickel and coking coal - industrial mainstays hard hit in the wake of China's economic pullback.
It took a $916 million impairment charge on its Australian manganese business, and a $518 million charge on its South African energy coal unit, underscoring the deterioration in industrial demand for imported raw materials in China.
Spun off last year by BHP Billiton BHP.AX BLT.L , South32 is the largest producer of manganese ore and a top producer of manganese alloy, used in making aluminium products such as drink cans.
The non-cash charges were flagged by the company on Feb. 4, along with plans to cut hundreds of jobs. Chief Executive Graham Kerr recently warned that challenging conditions and low prices would continue in the manganese market and called for supply-side discipline.
The half-year loss compared with a pro forma profit of $339 million a year ago.
Underlying earnings, excluding non-cash impairments and the impact of foreign exchange, slumped 94 percent to $26 million.
The company maintained its production guidance for the full year, but has cut capital expenditure by $150 million.
Shares in South 32, which have shed about half their value since first trading in May, fell nearly 3 percent in morning trade to A$1.09 before recovering to be flat in a slightly weaker overall market .AXJO .