News of the withdrawal came in a statement published in Turkish, a translation of which was carried by online news site Today’s Zaman.

In its statement, the broadcaster expressed dissatisfaction with the system, having seen its ratings drop consistently since April 2009.

TRT also reiterated claims it had made previously that TIAK had violated the country’s competition regulations. AGB Nielsen was similarly accused by TRT, however the Turkish Competition Board decided in November that there was no evidence or documents to support the allegations that AGB Nielsen was “exploiting its dominant position in ratings measurement by irregularities and false measurements”.

However according to Craig Johnson (pictured), AGB Nielsen’s managing director for Turkey, the Competition Board has found TIAK to be “lacking in structure and technical ability” and has given the joint industry committee 90 days from 5 January to restructure its organisation, hire full time professional staff and make its methodology publicly available.

Johnson was speaking following a meeting with TIAK earlier today, however representatives of the committee could not be reached for confirmation.

Following the meeting, Johnson revealed that TRT was bringing legal action against himself, TIAK president Ömer Kayal?o?lu and TIAK’s auditor Omur Cagli. Johnson said the state-owned broadcaster claims to have been financially harmed by an alleged leak of information about TV ratings panel members.

The accusations chime with claims made last June that the identity of panel members had been uncovered and that home owners were reportedly offered money by a third party to change their viewing habits. Johnson, however, said it would be “speculation” to link the bribery claims with the current accusations.

Regarding TRT’s withdrawal from the TIAK-commissioned ratings system, Johnson said AGB Nielsen had not been officially notified of the action, however he said he understood the broadcaster had signed a deal with local social research agency SBT Analysis to provide it with audience rating information starting this March.

TNS takes over the TIAK contract from AGB Nielsen from next year, after which TRT says it will reconsider its participation in the official TV measurement system, according to Today’s Zaman.

TRT could not be reached for comment at the time of publication.