MANILA – China's iron-ore benchmark scaled a record high on Thursday after miner Vale SA unveiled output targets that lagged forecasts, adding to concerns about weak seaborne supply.

Iron ore on China's Dalian Commodity Exchange ended daytime trade up 1.7% at 937 yuan ($142.86) a tonne, near its peak of 941.50 yuan. It now has gained more than 80% this year, making it the hottest major commodity of 2020.

The steelmaking ingredient climbed 1.1% to $132.50 a tonne on the Singapore Exchange by 07:17 GMT, advancing for the eighth consecutive session.

Brazil's Vale trimmed its 2020 output guidance to 300-million to 305-million tonnes, from a previous target of at least 310-million tonnes.

The 2021 production forecast of 315-million to 335-million tonnes, which took into account rainy conditions and other risks, also disappointed some analysts.

The disappointing forecasts added fuel to an iron ore rally that began last week, driven mainly by robust demand in top steel producer China and partly by supply concerns.

Spot iron-ore jumped to $133.50 a tonne on Wednesday, the highest since January 2014, according to SteelHome consultancy data.

China's iron ore demand revved up in the second half of 2020 as the world's second-largest economy is on track to become the first to fully recover from the Covid-19 pandemic. "China's infrastructure, property and manufacturing sectors have all surpassed expectations this year," Commonwealth Bank of Australia commodities analyst Vivek Dhar said.

Rising demand and weaker supply have both resulted in a tighter seaborne iron ore market, he said, citing ship-tracking data that indicated lower shipments from top supplier Australia in November.

Steel futures retreated after recent gains, with rebar on the Shanghai Futures Exchange down 1.2%, while hot-rolled coil slipped 0.2%. Stainless steel was flat.

Tight supply kept coking coal well supported, gaining 1.3%, while coke dropped 0.5%.