Revenue during the quarter dropped 16.77 percent to $88.11 million from $105.87 million in the previous year period. Total expenses were 69.24 percent of quarterly revenues, up from 69.23 percent for the same period last year. That has resulted in a contraction of 1 basis points in operating margin to 30.76 percent.

Operating income for the quarter was $27.11 million, compared with $32.58 million in the previous year period.

However, the adjusted EBITDA for the quarter stood at $51.06 million compared with $64.58 million in the prior year period. At the same time, adjusted EBITDA margin contracted 306 basis points in the quarter to 57.94 percent from 61 percent in the last year period.

"Although 2016 was a challenging year for the coal industry, NRP enters 2017 as a much stronger company," said Wyatt Hogan, president and chief operating officer. "The recent improvements in the markets for both metallurgical and thermal coal, combined with the continued balance and diversification of our soda ash and aggregates businesses, position NRP well for the new year."

Cash flow from investing activities was $166.82 million from investing activities during the year as against cash outgo of $30.27 million in the last year.

The company has spent $286.18 million cash to carry out financing activities during the year as against cash outgo of $171.46 million in the last year period.

Cash and cash equivalents stood at $40.37 million as on Dec. 31, 2016, down 2.02 percent or $0.83 million from $41.20 million on Dec. 31, 2015.

Debt comes down
Natural Resource Partners L.P. has recorded a decline in total debt over the last one year. It stood at $1,126.30 million as on Dec. 31, 2016, down 11.13 percent or $141.12 million from $1,267.43 million on Dec. 31, 2015. Interest coverage ratio deteriorated to 1.16 for the quarter from 1.43 for the same period last year.