* Vale could be hit with $15.1 bln bill if tax upheld
* Decision to impact Brazilian multinationals
RIO DE JANEIRO, April 3 (Reuters) - Brazil's Supreme Court on Wednesday put off for a week the judgment of a landmark case that will decide how the foreign profits of mining giant Vale SA and other multinationals are treated by tax authorities.
Vale alone faces 30.5 billion reais ($15.1 billion) in tax judgments related to the case, or 15 percent more than the company's average annual profit in the last three years.
The ruling will also impact other multinationals such as Cia Siderurgica Nacional, chemical maker Braskem SA and steelmaker Gerdau SA.
The court's 10 active judges will use the extra time to try to come to a majority decision in the case. The judges' opinions, plus an 11th written decision by a judge who recently left the court, differ too much to decide the case or create a clear precedent on how to tax foreign profits, justice Gilmar Mendes told reporters after the court's session in Brasilia.
Preliminary rulings, or votes, in the case, which has dragged through the Brazilian justice system for 12 years, combined with changes in the court suggest that the companies have a narrow edge over the government, Rodolfo De Angele and other JPMorgan Chase & Co. mining company analysts wrote in a Wednesday report to investors.
Chief Justice Joaquim Barbosa said he planned to vote that the tax rules are unconstitutional except for subsidiaries based in jurisdictions declared unfair tax havens by the Brazilian government. His, and all other judges' decisions, can change up to the moment that the court declares its final ruling.
Vale preferred shares, the company's most-traded class of stock, rose 5.8 percent and its common shares rose 6.5 percent in Sao Paulo Wednesday before the judges suspended their televised deliberations.
The preferred shares jump was the third biggest rise in two years. The common share rise was the biggest since September 2009.
The case, which is being led by Brazil's National Confederation of Industry (CNI), revolves around the treatment of foreign profits for Brazilian tax calculation. Brazilian companies object to their government's attempt to tax their foreign profits before the foreign subsidiaries repatriate the profits to the Brazilian parent.
The plaintiffs say that this is a second tax on foreign profits, which are already taxed by authorities where the subsidiary is based. To consider that foreign profit part of the Brazilian unit's profit before it returns home as dividends also results in taxation of changes in the value of the parent company's equity in foreign units.
"Foreign equity can rise even when foreign profit falls," said Paulo Ayres Barreto, who argued in front of the court for the CNI. "That's essentially taxing losses."
The government argued that its measures, introduced in 2001, were designed to prevent tax evasion through the use of foreign tax havens and to prevent investment and profits needed in Brazil from going abroad.