The State's companies' registrar yesterday warned that he plans to prosecute a number of businesses that have been consistently filing their annual returns late.

Fines paid by companies who failed to file their annual returns on time grew by almost €3 million between the beginning of the year and the end of August, compared to the same period last year, figures released yesterday show.

The Companies' Registration Office (CRO) issued figures that showed the total value of late filing penalties imposed on companies in the first eight months of year was €13.9 million, compared with €11 million during the same period in 2004.

Companies' registrar Paul Farrell blamed a "relatively small number of companies" that ran up large penalties while filing as late as possible.

Registered companies are obliged to file returns showing their share capital and shareholders every year, while all limited companies must also file annual accounts. These are the available to the public.

Mr Farrell warned yesterday that the CRO intended to root out the offending businesses through prosecution.

"We are now prosecuting non-filers for 2004, and we will be prosecuting for 2005 next March and April," he said.

"It's the repeat offenders that we are going for, the same companies hang on and hang on until they get a strike off notice, and then they file their returns. We will be going after them."

Late filing companies can be struck off, which removes the protection of limited liability, and they have to prove they are complying with the rules before being restored to the register.

They get 30 weeks notice before being struck off. However, Mr Farrell said that his office intended shortening this time period.