US seaborne exports of coal topped 90mt (million tonnes) last year as international steel production created strong demand in Asia.
This figure was more than 4 times the 20mt shipped in 2002 and comprised 59.3mt of coking coal and 31.5mt of steam coal, a report from shipbroker Simpson Spence & Young's consultancy and research team said.
This record beats the previous export record of 88.8mt in 1991.
The major contributing factor for US coal exports in 2011 came when the international steel industry faced a sudden tightening in coking coal supply, when Queensland in Australia faced its worded flood in years.