New orders for US manufactured goods fell for a second consecutive month in September, dragged down largely by a drop in commercial plane orders, official data released Tuesday showed.

The Commerce Department said new factory orders fell 1.0 percent in September, following a revised 2.1 percent drop in August, previously estimated at 1.7 percent.

The September report was the latest evidence of the continued sluggishness in the manufacturing sector, hit by a strong dollar and weakness in the energy sector amid low oil prices.

Excluding transportation orders, which tend to be volatile month-on-month, factory orders fell 0.6 percent in September.

Transportation orders dropped 3.1 percent last month, less than half the August decline. A big 36 percent decline in commercial aircraft and parts orders outweighed a pick-up in defense aircraft orders.

Total factory orders in September were down 7.2 percent from a year ago.

The weakness was broad. Orders for durable goods -- products expected to last at least three years -- fell 1.2 percent. Nondurable goods orders dropped 0.8 percent.

"Demand for many categories of manufactured goods continues to struggle from the effect of a stronger dollar, weak foreign demand and lower energy prices," said Barclays analyst Jesse Hurwitz.