SPECIALIST cleaning group Proventec has slashed pre-tax losses, but warned its figures are unaudited and a truer picture will not emerge until December, in a change to the Rodney Street firm’s reporting period.

Most of this year has been spent on negotiating a debt for shares swap with its largest shareholder, InnoConcepts NV, leading to a change in the group’s accounting period which has been extended to 18 months, to September 30, 2010.

Chief executive David Chestnutt said the unaudited figures take no account of impairments, and more precise data will be available in the 18- month report at the end of December.

The latest report shows a fall in revenues in the 12 months to March 31, from £14.99m to £14.44m, while pre-tax losses were cut from £28.64m to £2.78m.

The firm developed steam cleaning techniques which help eradicate hospital superbugs such as C-difficile and MRSA.

However, Cryojet, a new dry ice-based cleaning system it had developed, aimed at the petrochemical industry, has been discontinued.

Mr Chestnutt said: “We thought it had tremendous potential, but contractually there were difficulties and we thought the best option was to close it down at our end.”

Over the past 12 months, the group has won several contracts, including a £4m two-year deal to supply NHS services with cleaning materials.