U.S. consumer sentiment slipped last month to lowest level since October as Americans worried the country's economic outlook, the University of Michigan says.

The university's index of consumer sentiment dipped to 91 in March from 91.7 in February. Richard Curtin, chief economist of the Michigan surveys, said consumers' dim view of the economy offset improvement in their own finances. Last month's reading was the lowest since the index registered 90 October. A year earlier, it stood at 93.

Signs of economic weakness and rising gasoline prices have taken a toll on consumers' spirits.

AAA says the average gallon of U.S. gasoline costs $2.06, up from $1.76 a month ago.

Americans have grown cautious about spending. Consumer spending barely grew in December, January and February.