Moody's Investors Service on Wednesday lowered its outlook for Brazil's sovereign debt to "stable" from "positive", as Latin America's largest economy struggles with the impact of three years of low growth, weak investment And growing debt.

Moody's ratified the country's sovereign credit rating on "Baa2", the penultimate level of investment grade. The company improved its outlook to "positive" in 2011 and, at the end of last year, took the unusual measure of postponing its decision on a possible increase of the note in a year.

The decision points to growing market concerns that Brazil's economy, which at the end of the last decade was believed to be entering a period of vibrant expansion, is lagging behind other emerging markets.