Consumption of electrical power decreased 16 per cent and consumption of petroleum products fell 6 per cent in Massachusetts during the first week of the state's energy conservation program, a government official said yesterday.

Mary Newman, secretary of Manpower Resources, told an audience at the Design School that reports presented to Governor Francis W. Sargent at a Monday afternoon meeting indicated a large decrease in general energy consumption throughout the state.

Newman said the decreased consumption of fuel may alleviate some of the economic problems Massachusetts was expected to face this winter.

"If this strong public reaction continues," she said, "we can probably avoid the extra unemployment and economic dislocation that might occur if the energy shortage affected various industries."

However, in spite of the economic dangers of the fuel shortage, home heating oil remains the state's first priority in fuel allocation, she said.

"After that," Newman said, "I think we should give some consideration to industries which produce goods vital to production purposes in other industries."

Newman said the state's allocation mechanism--instituted after Governor Sargent's energy message last Tuesday--is "still very much in the planning stage."