Brazil keeps tax on ETFs as confusion over rules lingers

* Maintains tax on ETFs unchanged at 15 pct

* Seeks to stem investor confusion over tax

BRASILIA, Sept 10 (Reuters) - Brazil's government reaffirmed a 15 percent tax on investments in exchange-traded funds, seeking to stem confusion over taxation for alternative investments that has lingered for months.

Officials at Brazil's tax authority, known as Receita Federal, explained that amendments to regulation on taxation of different investments that were unveiled early on Mo nday sought to clarify doubts regarding taxes incurred by investments in so-called ETFs.

The tax authority changed the wording of a decree regarding the taxation of different investment structures, including funds on local corporate debt and other vehicles focused on research and development projects. The tax on ETFs will apply to purchase and sale of the securities in excess of 20,000 reais ($9,900).

"We wanted to clarify the rules governing these funds, specifically taxation levels when an investor enters and exits those funds," said Sandro Serpa, deputy secretary for taxation at the Receita Federal.

Investors have been puzzled by tax levies on asset-backed, private-equity and other alternative investment funds following measures last year by President Dilma Rousseff's administration to prevent the currency from rising against the U.S. dollar. Some of those measures included hiking taxes on offshore purchases of local debt notes.

ETFs are typically structured to track stock indexes and groups of related stocks. The securities are listed on an exchange and trade like a stock.

The outstanding amount of ETFs in circulation in Brazil is about 1 billion reais, Serpa said, compared with the more than 1 trillion reais in other types of investment funds.