Interserve shares have plunged by more than 10% on Monday evening to their lowest level since over 30 years.
The construction company’s shares closed at 39.03p, dropping from 45.18p as concerns grow over the group’s finances.
Chief executive Debbie White commented on the results this year and said it had been a “difficult year” with “much still to do.”
Shares in Interserve have declined by over 90% in the past five years.
Waste-to-product manufacturer, Renewi, said in their latest trading update that Interserve has missed a deadline for a joint project in Derby that is working to produce energy from waste.
One example is turning coffee waste into electricity.
Claire Perry, the energy minister, said: “Your morning latte could start its life on a remote Colombian coffee farm and now, thanks to UK-government funded research, those farms now have grounds to double up as producers of both coffee beans and electricity.”
Following the collapse of Carillion in January this year, Interserve accepted a £300 million rescue plan in March.
Speaking about progress at the Derby plant, a spokesperson said: “We continue to make progress on the Derby energy from waste project and can confirm that the construction completion certificate has been achieved. The plant is operational and already receiving waste, and we continue to commission the plant in readiness for handover.”
Shares in the group (LON: IRV) are trading -13.43% at 34.04 (1025GMT).