silver lake resources ltd said its annual net profit fell by 21 weighed by a noncash tax expense and rising production costs the mining company on monday reported a net profit of 777 million australian dollars us534 million for the year through june that compared to a profit of a982 million in the same period a year earlier silver lake recorded a noncash tax expense of a377 million and a gain of a288 million associated with its acquisition of harte gold it produced 3 more gold yearonyear and its average realized price rose by 7 but its production costs surged by 18 the company said