The 27-year-old soil engineer was investigating ground conditions in a deep trench on a development site in Stroud when it collapsed and killed him in September 2008.

The company will be sentenced on Thursday and could be fined a percentage of their turnover.

It is the first prosecution under the new Corporate Manslaughter and Corporate Homicide Act. The firm denied the charge of corporate manslaughter.

No-one was in the dock during the three-week trial as the director of the company Peter Eaton, 61, is seriously ill and unable to stand trial.

Mark Ellison QC, prosecuting, told the jury that Imperial College graduate Wright had worked for Cotswold Geotechnical for two years.

He said that Wright had been left to work alone in the 3.5 metre-deep trench to ‘finish-up’ after the company director had decided to leave for the day.

The two people who owned the development plot decided to stay at the site as they knew Wright was working alone in the trench. About 15 minutes later they heard a muffled noise and then a shout for help.

While one of the men called the emergency services, the other one ran to the trench where he saw earth had fallen in and buried Wright up to his head.

He climbed into the trench and removed some of the earth to enable the young geologist to breathe. But more earth fell into the pit covering the geologist completely. Wright died of traumatic asphyxiation.

The hearing was told the pit was unsupported, which the Crown alleged was against health and safety laws.

Speaking outside court Cotswold Geotechnical’s lawyer, said: “The company will over the coming days consider all of its options including any potential grounds for appeal.”

Cotswold Geotechnical Holdings said it “deeply regretted the tragic incident which resulted in the loss of this talented young man.”