Australia's Fortescue logged a near-record iron-ore shipments for the first half and kept full-year forecast unchanged on Thursday, as the mining giant ramps up production at its flagship Iron Bridge project.

The world's fourth largest iron-ore miner shipped 48.7-million tonnes of the steel-making commodity in the quarter ended December 31, bringing first-half shipments to 94.6-million tonnes, the second highest in the company's history.

Shares of the miner rose 2.5% to A$29.1 as of 23:03 GMT.

"Demand for Fortescue's suite of iron ore products remains strong and our entry into the higher grade segment of the market through Iron Bridge has been well received with our second magnetite shipment during the quarter," Fortescue Metals CEO Dino Otranto said.

Pricing for low grade iron-ore, which is the bulk of the firm's products, has found support as steel mills focus on conserving margins amid lingering weakness in China's construction sector.

The company, however, trimmed fiscal 2024 shipments forecast at its flagship Iron Bridge project to a range of two-million tonnes to four-milltion tonnes from five-million tonnes estimated earlier.

The Canning Basin Raw Water Pipeline at the project faced further leaks during the quarter, Fortescue said, impacting flow rate.

The magnetite project in the Pilbara region will allow the miner to blend high-grade output with its typically lower grade ore, raising average quality above 60%, making it more competitive when compared to BHP Group and Rio Tinto.

Fortescue kept fiscal 2024 total shipments estimates unchanged at 192-million tonnes to 197-million tonnes.

The firm had in early January flagged that multiple iron-ore cars had derailed from its tracks at Western Australia operations.

"An operational recovery plan has been implemented to optimise rail inload and shipments in second half of fiscal 2024," Fortescue said.