With inflation racing ahead and the LTN losing attractiveness because of their fixed yields, the ORTN continued increasing their share of the total public bond debt, reaching the highest level since the creation of the LTN, nearly 96%.
At the start of 1985, the ORTN corresponded to 97% of the total outstanding internal federal debt, while the LTN represented only 3%, with average maturity of less than a month (27 days).
The reduction of the average maturity of the debt was also influenced by the issuance in May 1985 of an ORTN falling due in one year, and during the year nearly all of these bonds were taken up by financial institutions.
After a prolonged period when the ORTN and LTN were the only instruments in the Brazilian open market, in 1986 significant changes were made in the conduction of the public debt and the very functioning of the financial system.
A second important change was creation, by BCB Resolution 1124/86 (May 1986), of another debt instrument, the Letras do Banco Central, or LBC ("Central Bank Notes"), whose main objective was to serve as a monetary policy instrument, taking the place of the LTN and ORTN. Given the difficulties of new LTN issues, and unable to use the ORTN (now OTN) indexed for inflation, because of the general price freeze, the Central Bank resorted to issuing its own bonds, legally allowed since its creation by Law 4595 of 1964.
At the end of 1986, the OTN had a 41.4% share of the total debt, in other words, less than half that of their predecessors the ORTN just one year before, and this fell further to 26.9% in 1987.
(1) Note in this respect that the introduction of the LTN followed the same strategy employed with the ORTN.
4.357 de 16/07/64 que criou as Obrigacoes Reajustaveis do Tesouro Nacional (ORTN) e institucionalizou a correcao monetaria.
Com a introducao da ORTN, o mercado passou a contar com um novo mecanismo que protegia o adquirente da depreciacao monetaria.
Assim, com o intuito de estimular o surgimento de um mercado para esses papeis, mesmo que este processo ainda fosse embrionario, o governo se valeu de alguns mecanismos que viessem a incentivar sua aquisicao como, por exemplo, a possibilidade de se utilizar as ORTN para pagamento de impostos da esfera federal e a permissao de serem utilizadas para a composicao, em parte, das reservas compulsorias dos bancos comerciais junto ao BCB, entre outras medidas.
Mesmo com aceitacao cada vez maior por parte do publico, as operacoes de mercado aberto nao conseguiam deslanchar, haja vista a ORTN ser um titulo com vencimento de longo prazo.
De acordo com Marinho (1986), as Letras do Tesouro Nacional foram criadas com o intuito de dotar o mercado de um titulo de caracteristicas mais simples e capaz de permitir uma maior flexibilidade e rapidez as operacoes de mercado aberto, as quais nao poderiam ser atingidas pelas ORTN, haja vista tais titulos serem mais apropriados para a captacao de poupanca a medio e longo prazo.