The firm, based in Merthyr Tydfil, was prosecuted for hiring out an excavator without suitable rollover protection and for failing to carry out pre and post-hire checks on equipment and hirers.
The charges were in relation to an incident in 2006 in which farmer Stephen Kidd rolled one of the company’s excavator’s over as he tried to level some uneven land on his property.
Mr Kidd was unable to jump clear as the machine rolled, trapping his leg underneath it for 40 minutes before he was released by emergency services. He suffered crush injuries to his foot and ankle.
Health and Safety Executive inspector Sarah Baldwin-Jones said no checks had been made by Astra Plant to ensure Mr Kidd was suitably trained to operate the machine before allowing him to hire it.
Her investigation also found rollover protection had previously been fitted to the machine, but was absent at the time of hire.
She said: "Companies hiring out equipment like this need to ensure that those hiring it are competent and are using the right equipment for the job planned.
"This was a serious case, and the failings could well have resulted in more serious injury or death to Mr Kidd."
The company pleaded guilty to both charges.