Citing company sources, the magazine said Vale, which already owns 27 percent of the Brazilian plant CSA, would be interested in buying the rest of the joint venture, which has saddled Germany's biggest steelmaker with heavy losses.

A Vale representative said on Saturday the company did not want to buy a controlling stake in any steel mill. But she did not rule out the company increasing its stake in CSA, so long as it did not become the majority stakeholder.

Vale, the world's second largest mining company, has long seen its business as mining, although it takes minority stakes in steel projects to stimulate production in Brazil and to create demand for its ore.

In May, Vale's chief executive told analysts the company "does not want to become a steelmaker" when asked about the sale of CSA.

Taking a majority stake and operating a steel mill would be a major shift in Vale policy. The company stopped owning and operating steel mills about 10 years ago.

POSCO has shown interest in Thyssen's mill in Alabama, according to an excerpt of a story to be published in the German magazine's Monday edition.

Posco, with partners Dongkuk and Vale, is building the CSP steel slab plant in Brazil's northeastern port city of Pecem. That plant produces a similar product to the ThyssenKrupp plant in Rio de Janeiro, but is more than a day and a half closer by boat to the Alabama plant.

ThyssenKrupp was not immediately available for comment.

Earlier this month, ThyssenKrupp Chief Executive Heinrich Hiesinger said he would offer the Brazilian plant to its partner in the slab-producing CSA plant venture and would also talk to possible buyers in Asia.

He put the book value of the two mills at 7 billion euros ($8.7 billion) - well below the company's investment in the growth projects of closer to 12 billion euros.

The plants in Brazil and Alabama were meant to give ThyssenKrupp a strategic foothold in the Americas just as the automotive and non-residential construction sectors were picking up in the United States.

ThyssenKrupp's CSA plant in Rio is one of the biggest foreign investment projects by value in Brazil to date.

But soaring costs in Brazil, in particular the strong currency, and rising input prices - combined with lackluster demand - eroded the logic of a strategy that should have seen slabs produced cheaply in Brazil and sold at advantageous cost to the United States.

(Reporting by Harro ten Wolde; Additional reporting by Reese Ewing in Sao Paulo; Editing by Mike Nesbit and Peter Cooney)

• A Permanent Economic Emergency