By Isabel Versiani and Pedro da Costa
WASHINGTON, April 14 (Reuters) - Brazilian Finance Minister said on Thursday he will push for tougher oversight of derivatives at this weekend's gathering of major world economies, blaming speculation for a run-up in commodity prices.
In an interview with Reuters, Mantega took a decidedly friendlier tone toward China despite what is widely seen as Brazil's disadvantage in exports market due to a lack of flexibility in the Chinese yuan.
"The primary responsibility for the excess liquidity lies with the advanced nations, not emerging ones," he said in response to questions about China's exchange rate, which many economists say is artificially undervalued. "Emerging countries are helping because they are pushing the international economy. So China contributes, Brazil contributes, Russia, India."
That was a shift from the minister, who is now working under a new president, Dilma Rousseff. She took over from the popular Luiz Inacio Lula da Silva at the start of this year. The comments suggest the United States may be losing an important ally in the fight against what it sees as the unfair advantage China gains from pegging its exchange rate to the dollar. (Editing by Leslie Adler)