Mining giant BHP Billiton Ltd. reported Tuesday that global iron ore production for the second quarter grew 16 percent year-over-year, but remained flat sequentially. Production of metallurgical coal grew 30 percent. Total iron ore production for the first half of 2014 increased 19 percent. The company also maintained its full-year production guidance for petroleum, copper, iron ore and coal businesses.

"Strong operating performance across our diversified portfolio in the December 2013 half year delivered a 10 per cent increase in production and volumes are expected to grow by 16 per cent over the two years to the end of the 2015 financial year," CEO Andrew Mackenzie said in a statement.

Meanwhile, smaller rival Rio Tinto Plc (RIO: Quote, RIO.AX,RIO.L) reported Wednesday that its global iron ore production for the fourth quarter grew 6 percent from last year.

Issuing its production report for the second quarter ended December 31, 2013, BHP said it recorded a 16 percent increase in production of iron ore to 48.87 million tons from the year-ago period. However, production remained flat with the prior quarter.

The world's largest mining company reported a 19 percent increase in first half production to 97.82 million tons from last year. Iron ore is the main raw material used for steel production. The company also achieved first half production records across ten operations and three commodities.

BHP noted that this was a strong first half of production as two of its major assets, Western Australia Iron Ore and Queensland Coal, achieved record production.

BHP's second-quarter production of metallurgical coal, which is also used in steel making, grew 30 percent from last year to 11.54 million tons, and increased 13 percent from the first quarter. Production for the first half also increased 22 percent to 21.73 million tons.

Meanwhile, energy coal production declined 5 percent from the prior-year quarter to 17.77 million tons. It also decreased 10 percent for the first half to 37.41 million tons.

The miner said its total petroleum production for the second quarter declined 4 percent from the year-ago period to 57.7 million barrels of oil equivalent or boe. Total petroleum production also decreased 1 percent in the first half.

The company's alumina production grew 10 percent to 1.35 million tons from last year. Aluminum production for the quarter increased 2 percent to 0.30 million tons from the year-ago period.

The company's copper production for the second quarter increased 6 percent to 439,900 tons, and production of Nickel grew 9 percent to 37,800 tons from last year.

For the first half of 2014, BHP's petroleum exploration expenditure was $285 million, of which $147 million was expensed. The company also spent $219 million on minerals exploration, of which $195 million was expensed.

Looking ahead to the full-year 2014, the company continues to expect total iron ore production of 192 million tonnes, total petroleum production of about 250 million barrels of oil equivalent, copper production of 1.7 million tonnes, and total energy coal production of 73 million tonnes.

BHP Billiton also noted that its share of capital and exploration expenditure for the 2014 financial year is expected to be US$16.1 billion, as planned.

"Iron ore and metallurgical coal were particularly strong and are very well positioned to achieve guidance, notwithstanding the general uncertainty that exists as we enter the wet season," Mackenzie added.

BHP closed Tuesday's regular trading session on the NYSE at $66.30, down $0.75 or 1.12% on a volume of 2.47 million shares. In the past 52 weeks, the stock has been trading in a range of $55.66 to $80.54.