Boeing Co. landed new four orders valued at $1.5 billion for its 747 jumbo jetliners, giving life to a program starved for sales amid waning demand for four-engine aircraft. The orders were reported on Boeing’s website Thursday and the identity of the customer wasn’t disclosed. The U.S. planemaker also reported that it delivered fewer jetliners than a year earlier as it navigates transitions for two long-range aircraft: the hump-nosed 747 and the 767. The new sales provide a much-needed lift for the 747-8, the latest model in a jetliner family that debuted in 1970 and ushered in an era of affordable long-range travel for the mass consumer market. Last year Boeing netted only two orders for the aircraft, which have a $379 million list price. The company has repeatedly slowed the 747 assembly line, most recently to an output of six jets a year, as the order book thinned. Boeing had 23 unfilled jumbo orders as of March, although the tally includes two planes already built for defunct Russian carrier Transaero Airlines that are in storage. Quarterly Deliveries The planemaker handed off 176 jetliners to customers in the first quarter compared with 184 a year earlier, according to a Boeing statement. Total orders rose to 139 from 116. Boeing and Airbus Group SE are planning to speed production of their narrowbody jets while simultaneously introducing upgraded versions, a difficult juggling act for the companies as they each roll the aircraft out of factories at a rate of 42 a month. Investors closely monitor deliveries to gauge revenues since the bulk of payments are handed over at that time. Boeing delivered 121 of its 737s during the first quarter, the same as a year earlier. Deliveries for its 747 jumbos fell to one from four amid dwindling demand. The planemaker handed off one 767 as it focuses on resolving delays that have plagued an aerial refueling version of the jet. The manufacturer is combining oversight of its 767 and 747 programs as part of an initiative spearheaded by commercial airplanes chief executive Ray Conner to flatten management and speed decision making.