The 60-day extension was announced Tuesday in the Official Gazette.
Chavez declared an emergency in February as a severe drought pushed water levels to precarious lows behind the Guri hydroelectric dam, which supplies 73 percent of Venezuela's electricity. Water levels have since risen.
Electricity expert Miguel Lara said the government had no choice but to extend the measures while it brings new equipment online and upgrades existing power plants to boost output.
Lara, who used to head a government electricity agency, said a lack of investment and maintenance has had a significant effect.
The rationing measures, which have been scaled back somewhat in recent weeks, include rolling blackouts in some parts of the country and fines for major users that don't meet government goals for reduced usage.
