New orders for long-lasting U.S. manufactured goods fell more than expected in April to record their largest decline in six months as aircraft and motor vehicle orders tumbled, a government report showed on Wednesday.

The Commerce Department said durable goods orders dropped 3.6 percent after an upwardly revised 4.4 percent rise in March, which was previously reported as a 4.1 percent increase.

Economists polled by Reuters had expected orders to decline 2.2 percent last month.

Durable goods orders are a leading indicator of manufacturing and the report suggested some cooling in factory activity as the auto sector deals with a shortage of parts following an earthquake in Japan.

Orders were pulled down by a 30 percent plunge in volatile aircraft bookings. Boeing took in just two aircraft orders, sharply down from the 98 it received in March, according to information posted on the plane maker's website.

Motor vehicle bookings dropped 4.5 percent, the largest decline since August, likely tracking an 8.9 percent dive in auto production during that month. U.S. manufacturing contracted for the first time in 10 months in April as a result of supply chain disruptions in the wake of the March earthquake.

Excluding transportation, durable goods orders unexpectedly fell 1.5 percent after a revised 2.5 percent rise in March, previously reported as a 2.3 percent increase. Economists had expected this category to rise 0.5 percent.

The report showed weakness across the board, with big declines in orders for machinery, capital goods, defense aircraft, communications equipment and computers. However, orders for computers and electronic products rose.

Non-defense capital goods orders excluding aircraft, a closely watched proxy for business spending, fell 2.6 percent last month after an upwardly revised 5.4 percent increase in March. Economists had expected a 0.2 percent gain from a previously reported 4.3 percent rise.

Shipments of non-defense capital goods orders excluding aircraft, which go into the calculation of gross domestic product, fell 1.7 percent.