
Bryan Benjafield, a 23 year-old accounts administrator at building firm Charminster, siphoned money from company accounts by writing cheques to himself, using bank transfers and withdrawing cash.
The money was then transferred to his Ladbrokes account where he used it to bet on poker, casino games, and sports betting.
The building firm, which had a turnover of £11m a year, has since gone into liquidation and staff have been made redundant. A new company called Charminster Construction has since been set up.
The theft was only discovered when a tax official contacted the company to enquire about an unpaid tax bill.
Benjafield was released on bail by Dorchester Crown Court and will be sentenced at a later date.