UPDATE 1-Teck Resources Q4 adjusted profit in line with estimates

(Adds details, background)

TORONTO, Feb 14 (Reuters) - Canada's Teck Resources Ltd , the world's second-biggest exporter of steelmaking coal, reported an in-line fourth-quarter adjusted profit as lower operating costs helped offset a fall in sales of metallurgical coal.

Teck, which also mines copper, zinc and gold, said its adjusted profit fell to C$700 million, or C$1.21 per share, in the three months to end-December, from C$930 million, or C$1.61 per share in the same year-ago period.

On average, analysts had expected earnings of C$1.20 a share, according to Thomson Reuters I/B/E/S.

Net income rose to C$760 million in the fourth quarter ended Dec. 31, from C$697 million in the year-ago quarter.

Revenue fell 10.9 percent to C$3.21 billion.

The Vancouver-based miner sold 6.4 million tonnes of steelmaking coal, at an average realized price of $170 per tonne, in the fourth quarter, in line with its December forecast for 6.5 million tonnes of output at an average price of $165 to $170 per tonne.

Teck warned in October that a larger proportion of fourth-quarter coal sales were in non-premium coal, reducing its average realized price to about 85 percent of benchmark prices, from a typical 90-95 percent range. It expected the situation to correct going into 2018.

An environmental permit is expected in early 2018 for the project, which requires major infrastructure to transport sea water, which will be pumped from the coast and desalinated.

Production was hit last month when a dryer exploded at its Elkview mine, cutting steelmaking coal output by some 200,000 tonnes, Teck said at the time.

Teck said its decision to proceed with the development of second-phase Quebrada Blanca project will be contingent upon regulatory approvals and market conditions and is not expected before the second half of 2018.

The average fourth-quarter price of coking coal rose more than 7 percent from the third quarter while zinc prices climbed 8.8 percent, RBC Capital Markets said in a report. (Reporting by Susan Taylor and Shubham Kalia; Editing by Gopakumar Warrier and Sunil Nair)