The FCA has fined Asia Resource Minerals £4.7m for breaching the listing rules.
The regulator says the firm had inadequate systems and controls to comply with its obligations as a listed company.
ARM was admitted to the premium section of the official list on 28 June 2011.
On 19 April 2013, the company notified the UK Listing Authority that it would be unable to publish its 2012 financial report within the deadline. This was due to an ongoing review of the integrity of a number of items on the balance sheet of its subsidiary, PT Berau Coal Energy Tbk.
The review included historic potential related party transactions worth £8m which the firm had failed to identify.
On 22 April 2013, the company’s shares were suspended from trading for three months.
The FCA says the firm’s “significant” failings meant investors did not have the appropriate level of protection.
FCA acting director of enforcement and market oversight Georgina Philippou says: “The related party transaction rules protect minority investors in listed companies by ensuring that large shareholders and company directors do not unfairly benefit from their position.
“ARM should have been alive to the need for robust systems and controls to clearly identify related party transactions. ARM fell below the standards we expect; the failings were serious and went on for two years and ultimately led to the suspension of the company’s shares.
“We expect listed companies to comply with the UK Listing Rules from day one of listing and the penalty in this case demonstrates that we will take strong action when companies fail to meet the required standards.”
ARM agreed to settle at an early stage in the investigation and therefore qualified for a 30 per cent discount. Were it not for this discount the FCA would have imposed a fine of £6.6m.