By John S. McClenahen Analysts were looking for U.S. factories to add a tenth of a percentage point to new orders in August, following a 1.7% increase in July. They didn't. Data released on Oct. 4 by the U.S. Commerce Department show factory orders in August edged downward a tenth of a percentage point to $370.5 billion. New orders for manufactured durables, generally big-ticket items designed to last at least three years, were the major reason for the decline. They decreased 0.3% to $195.8 billion, with transportation equipment, particularly aircraft, posting the biggest decline: down 7.4% to $55.1 billion. New orders for nondurable goods, in contrast, increased in August, up 0.2% to $174.7 billion. Factory shipments, up five of the last six months, rose 1.1% in August to $376.1 billion, and factory inventories increased 0.5%, half their July 1% rise, to $460.9 billion.