July 14 (Bloomberg) -- Brazilian utility stocks fell to the lowest in three weeks after Valor Economico reported regulators plan to adopt accounting rules that may reduce the value of assets at companies that get government concessions.

Utility companies in the MSCI Brazil Index declined 1.1 percent, the most among the 10 industry groups. CPFL Energia SA, Brazil’s largest private-sector power distributor, dropped the most in almost a month, declining 3 percent to 30.20 reais. Cia. Energetica de Sao Paulo, the third-largest electricity- generation utility, fell 5.4 percent to 18.85 reais.

Brazil plans to adopt international accounting standards that may prevent certain assets from being booked on utilities’ balance sheets, Valor reported.

“This may be pressuring the sector a bit,” said Januario Hostin Jr., who oversees about 60 million reais at Leme Investimentos in Florianopolis, Brazil. “This could decrease the value of their assets.”

The country’s accounting regulator plans to adopt the standards next year, the Sao Paulo-based newspaper said. The electricity regulator, known as Aneel, will review the rules for the industry by the end of this year, Valor said.

To contact the reporter on this story: Catarina Saraiva in New York at Asaraiva5@bloomberg.net.

Last Updated: July 14, 2009 18:11 EDT