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9. INVESTMENTS (Details) - BRL (R$) R$ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of fair value measurement of assets [line items] |  |  |  |
Assets | R$ 47,327,524 | R$ 45,209,970 |  |
Shareholders' equity | 10,013,440 | 8,288,229 | R$ 7,384,521 | R$ 7,091,288
Fair Value Allocation | 271,116 | 271,116 |  |
Profit (loss) for the year | (5,200,583) | (111,229) | R$ 853,058 |
Classified as available for sale |  |  |  |
Usiminas | 2,250,623 | 2,200,459 |  |
Panatlantica | 28,566 | 21,974 |  |
Classified as available for sale | 2,279,189 | 2,222,433 |  |
Others investments |  |  |  |
Others investments | 112 | 76 |  |
Total Investments | R$ 5,359,497 | R$ 5,228,879 |  |
Joint Venture/Joint Operation 1 |  |  |  |
Disclosure of fair value measurement of assets [line items] |  |  |  |
Joint venture and joint operation name | MRS Logística S.A. |  |  |
Number of common shares held by CSN | 126,716,070 |  |  |
Direct equity interest, joint venture and joint operation | 37.27% | 37.27% |  |
Assets | R$ 3,125,912 | R$ 3,039,761 |  |
Liabilities | 1,693,200 | 1,714,729 |  |
Shareholders' equity | 1,878,095 | 1,782,162 |  |
Profit (loss) for the year | R$ 194,403 | R$ 171,905 |  |
Joint Venture/Joint Operation 2 |  |  |  |
Disclosure of fair value measurement of assets [line items] |  |  |  |
Joint venture and joint operation name | CBSI - Companhia Brasileira de Serviços de Infraestrutura |  |  |
Number of common shares held by CSN | 1,876,146 |  |  |
Direct equity interest, joint venture and joint operation | 50.00% | 50.00% |  |
Assets | R$ 25,941 | R$ 16,005 |  |
Liabilities | 19,997 | 13,654 |  |
Shareholders' equity | 5,944 | 2,351 |  |
Profit (loss) for the year | R$ 4,501 | R$ 1,785 |  |
Joint Venture/Joint Operation 3 |  |  |  |
Disclosure of fair value measurement of assets [line items] |  |  |  |
Joint venture and joint operation name | Transnordestina Logística S.A. |  |  |
Number of common shares held by CSN | 24,168,304 |  |  |
Direct equity interest, joint venture and joint operation | 46.30% | 46.28% |  |
Assets | R$ 4,065,604 | R$ 3,806,380 |  |
Liabilities | 2,883,851 | 2,604,198 |  |
Shareholders' equity | 1,181,753 | 1,202,182 |  |
Fair Value Allocation | 271,116 | 271,116 |  |
Profit (loss) for the year | (20,429) | (21,357) |  |
Joint Venture/Joint Operation |  |  |  |
Disclosure of fair value measurement of assets [line items] |  |  |  |
Assets | 7,217,457 | 6,862,146 |  |
Liabilities | 4,597,048 | 4,332,581 |  |
Shareholders' equity | 3,065,792 | 2,986,695 |  |
Fair Value Allocation | 271,116 | 271,116 |  |
Profit (loss) for the year | R$ 178,475 | R$ 152,333 |  |
Associate 1 |  |  |  |
Disclosure of fair value measurement of assets [line items] |  |  |  |
Associate name | Arvedi Metalfer do Brasil |  |  |
Number of common shares held by CSN | 46,994,971 |  |  |
Direct equity interest, associate | 20.00% | 20.00% |  |
Assets | R$ 40,712 | R$ 43,653 |  |
Liabilities | 26,308 | 23,978 |  |
Shareholders' equity | 14,404 | 19,675 |  |
Profit (loss) for the year | (5,087) | (4,368) |  |
Associate |  |  |  |
Disclosure of fair value measurement of assets [line items] |  |  |  |
Assets | 40,712 | 43,653 |  |
Liabilities | 26,308 | 23,978 |  |
Shareholders' equity | 14,404 | 19,675 |  |
Profit (loss) for the year | R$ (5,087) | R$ (4,368) |  |

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