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7. MARKETABLE SECURITIES (Details) - BRL (R$) R$ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Disclosure of Investment Securities [line items] |  |  |
Current investments |  | R$ 740 | R$ 704
Non-current investments |  | 13 | 109
Investments |  | 753 | 813
Financial Notes Banks [Member] |  |  |
Disclosure of Investment Securities [line items] |  |  |
Current investments | [1] | 645 | 435
Non-current investments | [1] | 11 | 109
Treasury Financial Notes [Member] |  |  |
Disclosure of Investment Securities [line items] |  |  |
Current investments | [2] | 94 | 254
Debentures [Member] |  |  |
Disclosure of Investment Securities [line items] |  |  |
Current investments | [3] |  | 11
Non-current investments |  | 2 |
Other Investment [Member] |  |  |
Disclosure of Investment Securities [line items] |  |  |
Current investments |  | R$ 1 | R$ 4
[1] | Bank Financial Notes (Letras Financeiras, or LFs) are fixed- rate fixed-income securities, issued by banks and that accrued interest a percentage of the CDI rate published by Cetip. The LFs had remuneration rates varying between 101.95% and 113% of the CDI rate in 2019 (102% and 111.25% in 2018 and 102.01% to 112% in 2017).
[2] | Treasury Financial Notes (LFTs) are fixed-rate securities, their yield follows the daily changes in the Selic rate between the date of purchase and the date of maturity.
[3] | Debentures are medium and long term debt securities, which give their holders a right of credit against the issuing company. The debentures have remuneration varying from 108.25% to 113% of the CDI Rate in 2019 (104.25% to 151% of CDI in 2018 and 104.25% to 161.54% of CDI in 2017).

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