Brazil's biggest diversified steelmaker Cia Siderurgica Nacional (CSN) said on Monday it signed a deal giving it a consolidated 87.52% stake in a new joint venture, Congonhas Minerios SA, with a group of Asian partners.

Partners including Japan's Itochu, Nisshin Steel Co Ltd, JFE Steel Corp and Kobe Steel Ltd, as well as South Korea's Posco Ltd and Taiwan's China Steel Corp will hold a combined 12.48% stake in Congonhas.

Congonhas combines CSN's Casa de Pedra iron ore mine with Namisa, another joint venture between CSN and Asian steelmakers. The stakes were calculated on the venture's estimated value of $16 billion and debt of $850 million, which had been on CSN's balance sheet.

The project is seen as a way to ease tensions among partners in Namisa, in which CSN has failed to fulfil a multiyear expansion plan. The new deal would free CSN from paying a $3 billion penalty to its Asian partners and reduce the debt on its balance sheet.

Congonhas also includes logistic assets, including the Tecar terminal at the Itaguai port in Rio de Janeiro and an 18.63% stake in the railway line MRS Logistica, which CSN now holds. It will also have a 40-year supply contract to sell iron ore to CSN and the Asian partners. CSN also secured a long-term contract to import raw materials through Tecar.