A TOT source said TOT would also ask CAT to demand compensation from the two operators at twice the unpaid amount, as permitted under CAT's concession terms.

Total Access Communication (DTAC) and True Move stopped paying access charges to TOT last November because they wanted the access charge replaced by interconnection charges.

The access charge is what DTAC, True Move and Digital Phone - all holders of concessions from CAT - have paid to TOT for connecting their calls to other networks via TOT's facilities.

According to TOT's access-charge contracts with all CAT concession holders, TOT can demand CAT to pay the access charges on behalf of its concession holders if they decline to pay TOT.

The TOT source said CAT has agreed in principle with TOT's plan to seek payment for access charges from CAT but CAT has to get the consent of its board and its 100-per-cent shareholder, the Finance Ministry.

The interconnection regulations of the National Telecommunications Commission call for all telecom operators to share voice and data revenues between the networks involved in calls on a fair and proportionate basis.

The operators have struck deals with each other over interconnection rates.

The regulator last week ordered TOT to enter into negotiations with DTAC on the interconnection-charge agreement within seven days after the order and said the talks must be wrapped up within the following 30 days.