Boeing registered orders for new cargo aircraft last month, but with the coronavirus ravaging the aviation and travel industry, cancelations continued to deal a heavy blow on the business.

The company disclosed nine orders and twice as many cancellations, including a switch of a delivery slot for a UPS 747 transporter.

The canceled orders included two dozen of its 737 Max aircraft, the besieged plane that was grounded following two deadly crashes that claimed the lives of 346 passengers since March last year.

The American jet manufacturer disclosed that it delivered just four aircraft last month, down from the six it rolled out in April, its lowest monthly total in 60 years, and about 87 percent less than it delivered to buyers a year ago in the same period. 

Deliveries are financially crucial for aircraft manufacturers, because when they actually receive the plane, the companies pay most of the order price.

In May, clients also called off deliveries for another batch of 18 aircraft, including 14 MAX jets that were the best-selling jets of the company until a pair of accidents just over one year ago.

Leasing companies, which control more than 40 percent of the world's fleet, are one of the biggest MAX buyers. The demand for cargo planes, an area separating Boeing from its competitor Airbus, was a promising segment for the company last month.

The size of Boeing's fleet, which includes three different types of cargo planes, and the transformation of commercial planes into cargo usage, is an edge over its European rivals. Airbus has just extended its service to include express freight planes.

During the COVID-19 pandemic, demand for cargo capacity increased. Besides the need to transport medical supplies and personal protective equipment, cargo for other products has been cut by 50 percent with too many commercial aircraft parked because of lack of demand for consumer travel. Passenger flights usually also carry high-value cargoes that include fresh produce and electronics.

Boeing's backlog was reduced to 4,744 aircraft, the lowest since 2013, including orders that it routinely excludes from its list as a result of financial difficulties or other factors on certain clients, a practice Boeing did not have in place during that time. 

In midday trading, the company's shares were down over 3 percent. In the last few weeks, the stock of the manufacturer has rallied nearly 70 percent as signs of passengers returning to air travel lifted the sector, but its shares are still down more than 30 percent so far for 2020.