Global miner BHP Billiton Ltd (ASX:BHP) has reported record iron ore production and shipments for both the half year and quarter ended December 2010 despite the impact of ongoing tie-in activities related to its growth projects.

In the December quarter, BHP produced a record 33.6 million tonnes or iron ore, with an annualised production rate of 148 million tonnes from Western Australia. Robust growth in developing economies remains the primary driver of commodity demand and further positive signs are emerging in the United States following the Federal Reserve's ongoing efforts to stimulate the economy, according to the miner.

"When coupled with supply side constraint, which has been further exacerbated by weather related disruptions in countries such as Australia, Colombia and South Africa, BHP Billiton remains confident in the fundamentals for its core products," it said.

But coal production in the same quarter has been significantly impacted by Queensland's severe weather conditions.

In the December 2010 quarter, Queensland Coal production declined by 30 per cent when compared with the September 2010 quarter. The decline in Queensland Coal sales, however, was limited to 15 per cent and benefited from the relatively healthy level of inventory that was held across our supply chain at the commencement of the quarter.the miner said it continues to assess the impact of the extreme weather events and confirms that force majeure has been declared for the majority of our Bowen Basin products, including Goonyella Riverside, Peak Downs, Norwich Park, Gregory Crinum, South Walker and Blackwater.

The miner has also warned that it expects an ongoing impact on coal production, sales and unit costs for the remainder of the 2011 financial year.

Shares in BHP slid 1.68 per cent after the announcement today, losing 0.78 cents to $45.28, as the benchmark S&P/ASX 200 index was down 0.55 per cent.