This excerpt taken from the TGS 20-F filed Jun 27, 2006.
INVOICING AND PAYMENT TERMS
The quantities of Ethane to be invoiced by TGS to PBB shall be those measured on the basis of data obtained from the Meter Stations located at the Point of Delivery to PBB and the Point of Delivery to the Transporter (FR-501) downstream of General Cerri Complex.
TGS shall invoice to PBB on a monthly basis, the quantity of delivered metric tons of Ethane. The invoices and/or debit notes shall be issued in United States dollars. Notwithstanding the foresaid, PBB may pay the amount of the invoices in national currency, for which it must take into account the selling today value dollar quote of the Banco de la Nación Argentina on the working day previous to the date of the payment; for such purposes, payment shall be conducted at TGS domicile. If the specified quotation should not exist, the quote shall be the one that allows to buy the required dollars with national currency at the date of the maturity of the invoice payment in the markets of Montevideo, República Oriental del Uruguay or New York, United States of America.
12.3 The payment may be made by means of check drawn on a bank of the Autonomous City of Buenos Aires, the amount of which may be credited to TGS check account on the due date of the invoice or in the previous day if the due date is not a working day; or by means of a bank draft to the order of TGS, subject to TGS instructions.
The payment of value added tax (V.A.T.- I.V.A. in Argentina) corresponding to each sale shall be discriminated in each invoice and shall be paid together with the invoiced price in accordance with the stipulations set forth in the preceding paragraph.
The payment term shall be of ten (10) consecutive days as from the date of the reception of the invoice on the part of PBB. For those purposes, PBB agrees to consider as the invoice receipt date, the date on which it has received a copy of same via fax, at its offices located in the Polo Petroquímico of the City of Bahía Blanca.
The default of the payment obligation shall occur by operation of law, without need of previous claim. A monthly interest equivalent to the Libor Rate of one month plus 500 basic points shall accrue from the maturity date of the invoice until the date the payment is effected.
Upon expiration of the ten-day term for the payment of the invoices, TGS shall be entitled to suspend all delivery of Ethane until PBB pays off the invoice in arrears as well as the accrued interests. Thirty (30) days upon expiration of the payment term of the invoice, the default of the obligation of payment shall entitle TGS to rescind the contract and put a claim for the resulting damages.
Should there be observations to the invoices and/or credit or debit notes, PBB shall present the corresponding claim in writing within five consecutive days upon receipt of the invoices. If the claim is made before the maturity of the invoices and/or debit notes, PBB must pay the unquestioned amounts upon their maturity.
If upon maturity of the invoices and/or debit notes, PBB has not filed any claim, it must pay the aggregate amount without detriment to the right to formulate the corresponding observations in order to file the relevant claims in a term of twenty (20) consecutive days upon receipt of the
invoices. Upon expiration of such term, PBB shall not be entitled to present any claim, and in that event TGS may repeal those claims by operation of law.
If the observations submitted by PBB were turned down by TGS on reasonable grounds, then the claimed amounts that have not been paid must be settled by PBB ten days upon receipt of the Certifiable Notice of the mentioned turndown by TGS and a punitive interest shall accrue on said amount pursuant to 12.6 of this Article, calculated for the period ranging from the date on which the payment should have been made and the date the payment is effected.
Notwithstanding the preceding considerations, PBB shall not waive its rights to continue with the claim of the questioned balances, and in the event that PBB claim is upheld by means of final judgment by an competent arbitration court, PBB shall be entitled to claim punitive interests on all the amount unduly paid, calculated in accordance with the stipulations of section 6 of this Article as from the date of the effecting of the payment.