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

CPST is set between the transmission concessionaire and the National Power System Operator - ONS, aiming to establish the terms and conditions that will govern the conditions of administration and coordination by the ONS, the provision of transmission services by the transmission concessionaire to the users of the BIPS.

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

CUST is set between the user, the ONS and the transmission concessionaires, represented by the ONS, with every user and every agent connected to the transmission system or that eventually will make use of it. CUST, in general, aims to establish the terms and conditions that will regulate the use of the Basic Network by users. 

With respect to procurement, in 2013, 16 new contracts for Provision of Transmission Services – CPST were signed, 101 new Contracts of Use of Transmission Systems - CUST, 124 new contracts Connection to Transmission Systems - CCT and Sharing Agreements Facilities - CCI.

Among these, we highlight the celebration of 56 CUSTs regarding enterprises of wind power generation, which represent an important milestone in the integration of this source of renewable energy to the Brazilian energy matrix process.

In the year 2013 there has been also the start of the validity of CPST for the first dipole of the transmission system of the  Madeira river and consequently the payment of the Allowed Annual Revenue of transmission utilities that allow Santo Antônio HPP Jirau to deliver its power directly to the southeast region.

Also in 2013 the hiring of the use of the transmission system associated with the integration of System Acre / Rondônia BIPS was concluded thanks to the solution of the issues associated with the incumbencies of use of UTE Termonorte II. CUST with the Energy Company of Amapá was also set, which was an important milestone in the integration of Federal Unit to BIPS.

Finally, there is the joint that led to hiring the use of the transmission system on a temporary basis by UTE Uruguaiana in order to meet the recommendation of CMSE derived from the energy scenario for 2013.