(Updates with fresh details throughout)

By Monica Vargas

SANTIAGO, July 24 (Reuters) - Rains that refilled hydroelectric reservoirs have made it less likely that Chile will need to order rationing of electricity, and voluntary cuts in power use by the public also have helped, Energy Minister Marcelo Tokman said on Thursday.

Chile's government this month lowered its 2008 economic growth forecast to 4.2 percent from a previous estimate of 5.3 percent, citing the impact of high oil prices on a land that must import nearly all of its energy needs.

A severe drought, which the government described as the worst in decades, had forced power providers to rely on expensive-to-run diesel generators. Compounding the problem, neighboring Argentina restricted natural gas exports to Chile.

"The probability of rationing has fallen considerably," Tokman told reporters in the Chilean capital, Santiago.

"We can't completely rule out (an energy) deficit. We must be prudent," he added.

But Tokman warned that despite the rains, average reservoir levels remained below normal.

Snow accumulation also was below normal for the time of year, prompting fears of lower meltwater volumes, he added. Also, it remained unclear if generator Colbun's COL.SN Nehuenco power plant would resume operations in September after being closed after a fire late last year.