"The results were attributable to non-recurring impairment charges of RM283mil compared to a non-recurring net profit of RM2.23bil reported in the corresponding quarter last year, as well as a lower recurring PBIT," it said in a stock exchange filing.
The impairment charges mainly consisted of RM112mil for the group's long-term assets in Liberia and a further RM157mil in its investment in an associate company, Verdezyne Inc.
Meanwhile, recurring PBIT fell 22% due to weaker crude palm oil and palm kernel prices and marginally lower fresh fruit bunch (FFB) production.
The group said the decline in earnings was mitigated by lower finance costs of RM44mil arising from lower borrowings.
For its full financial year, Sime Darby Plantation posted a net profit of RM1.72bil compared to RM3.51bil in the previous year.
It said it recorded a non-recurring PBIT of RM517mil versus the non-recurring net profit of RM2.23bil from the sale of land in the previous year.
In Q4, the Malaysian upstream operations posted a recurring PBIT of RM243mil, 36% less than RM380mil in the year-ago quarter.
Upstream PNG and Solomon Islands also reported lower recurring PBIT of RM77mil versus RM219mil previously.
Upstream Indonesia rose 96% to RM92mil due to higher FFB production and lower production costs.
Meanwhile, Upstream Liberia narrowed its losses to RM9mil from RM26mil in the same quarter in 2017.
For the quarter under review, downstream operations posted a recurring profit of RM68mil versus RM7mil due to better earnings from the differentiated products business.
Other operations turned a loss of RM21mil in 4Q'FY17 to a recurring PBIT of RM1mil.
The board of directors has proposed a single-tier dividend of 11.5 sen.
Special single-tier dividends that have also been proposed include a cash interim dividend of three sen per share and a final dividend of three sen per share.