The Financial Services Authority has fined Jonathan Malins, the finance director of AIM-listed Cambrian Mining, a record £25,000 for twice buying Cambrian shares ahead of company announcements likely to move its share price.

The FSA ruled that Malins' purchases amounted to market abuse with the fine the largest the financial regulator has imposed for misuse of information.

Despite Malins still holding the shares, the FSA believed that if he had sold them on the days in question, he would have made a total profit of £6,400.

A spokesman for the FSA said: 'A reasonable person who regularly deals on AIM should regard Mr Malins' behaviour as a failure to observe the standard behaviour reasonably to be expected of any investor and certainly that of a finance director of an AIM company.'

Malins told the Financial Times that he accepted the FSA's criticisms, though he stressed he had not profited from the transactions. He said he had no intention of resigning and remained a buyer of shares.