Pre-tax profit at coal producers Hargreaves, owners of the soon-to-close Muir Dean opencast mine in Fife, fell almost 95% in the last six months.
Interim chairman David Morgan said that the market conditions in the UK coal and steel sectors remain very challenging.
The impending closure of the Longannet power station near Kincardine has hastened the end of Muir Dean near Crossgates.
The move by the coal supplier marks the end of major coal extraction in Fife and will cost jobs.
Hargreaves said global commodity markets face significant pressures.
The results for the six months to November 2015 reflect the difficulties encountered by the group’s coal and steel industry activities.
Revenue of £174.8 million was down 50.2%, reflecting the impact of lower volumes of coal sales for production and import businesses.
Continuing pre-tax profit was down 94.7% at £800,000 from £15.2m.
In a review of business, the group stated: “Significant falls in international coal prices have made our coal production operations loss-making.
“Changes in carbon taxes in March 2015 and a dramatic fall in gas prices have significantly reduced the demand for thermal coal from UK power stations in the first half.
“In response to these challenges, the group has reduced production levels in its Scottish operations.”
Scottish coal production is being cut back to a single site at House of Water in east Ayrshire, with the focus on producing speciality coals.
Falls in gas prices have also significantly reduced the profitability of coal generation, and demand for power station coals has reduced to negligible levels.
Finance director Iain Cockburn said Muir Dean was scheduled to shut in July but the closure is being advanced because of the Longannet situation.
“Work there is now transferring to site remediation, where there will continue to be a requirement for personnel,” he said.
Up to 15 jobs would be lost with the ending of opencast operations, but Hargreaves would do all in its power to redeploy its workforce.
Elsewhere in Fife, Hargreaves’ 350-acre Westfield site near Glenrothes has been identified for residual waste disposal.
A regeneration plan has been formed subject to a master planning exercise and includes an energy from waste facility as anchor development of a green energy park.
At the former opencast mining site at St Ninians/Loch Fitty near Kelty, a master planning exercise is in progress to develop the site for leisure and housing.
Hargreaves’ recent acquisition of civil engineering company Blackwell for £11.85m was a step to broaden the property portfolio.