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v3.19.1

RELATED-PARTY TRANSACTIONS - Operations with related parties, guarantees granted (Details) - Financing Agreements - BRL (R$) R$ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Joint-venture | Diaco S.A. |  |  |
Guarantees granted |  |  |
Original Amount | R$ 137,700 |  |
Carrying Amount |  | R$ 128,019 |
Joint-venture | Gerdau Corsa S.A.P.I de C.V. |  |  |
Guarantees granted |  |  |
Original Amount | 1,875,345 |  |
Carrying Amount | 1,933,929 | 1,797,856 | R$ 2,016,260
Joint-venture | Gerdau Summit Aos Fundidos e Forjados S.A. |  |  |
Guarantees granted |  |  |
Original Amount | 130,164 |  |
Carrying Amount | 41,571 | 6,550 |
Subsidiary and Joint-venture | Gerdau Metaldom S.A; Aceros Corsa S.A De C.V |  |  |
Guarantees granted |  |  |
Carrying Amount | R$ 198,619 | R$ 178,200 |

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