The transmission contracting process coordinated by ONS involves the development of two major contracts: CPST - Contract for Transmission Services and CUST - Contract of Use of the Transmission System.

CPST is celebrated between the transmission utility and the Operator - ONS, aiming to establish the terms and conditions which will govern the administration and coordination, by ONS, of the provision of transmission services by the transmission utility to the BIPS.

CPST is also the instrument of granting through which the transmission utility allows ONS to perform all acts necessary and sufficient to represent it before users in Contracts of Use of the Transmission System - CUST and its safeguard mechanisms .

CUST is celebrated between the user, ONS and transmission utilities, represented by ONS, and any and all agent connected to the transmission system or that will make use of it. CUST, in general, aims at establishing the terms and conditions that will regulate the use of the Basic Grid by users. 

It is worth noting that, in 2012, another important milestone was reached in the integration of Santo Antônio and Jirau, members of the Madeira River Hydroelectric Complex and recognized throughout society as an important structuring project for the country, with the celebration of Contracts of Use of the Transmission System - CUST for these plants.

Also deserves mention the contracting for the use of the transmission system of another major structuring project in the country, Belo Monte, since it was celebrated the CUST on Pimental plant- secondary powerhouse of Belo Monte power plant with 233.1 MW of installed capacity. The contracting of the use on the main powerhouse of Belo Monte plant, with 11,000 MW of installed capacity, will occur between 2014 and 2015.

With respect to contracts, 31 new contracts for Provision of Transmission Services - CPST, 107 new Contracts of Use of Transmission Systems - CUST, 108 new contracts for Connection to Transmission Systems - CCT and Sharing Facilities Contracts- CCI were signed in 2012.

Among these, we highlight the celebration of 79 CUSTs regarding wind generation projects, which represents an important milestone in the process of insertion of this renewable energy source in the Brazilian energy matrix.

In this context, is of great relevance the performance of ONS with the Grant Authority, ANEEL and agents, in order to provide the necessary adjustments in the transmission contracts aiming at meeting the provisions of Provisional Measure no. 579, current Law no. 12,783, which extended the concessions of generation, transmission and distribution of electricity and demanded these adjustments.