Boeing Co said on Wednesday it was halting 777X production through 2023 due to a fresh delay in its entry into service after certification problems and weak demand, with $1.5 billion in abnormal costs for the mini-jumbo program.

Shares of the U.S. planemaker fell 4% to $160.39 in premarket trading after it posted a quarterly loss and disclosed more than $1.2 billion in charges due to supplier costs and technical problems on its Air Force One presidential plane, trainer jet, and the war in Ukraine.

"Another dreadful set of results," Agency Partners analyst Nick Cunningham said in a client note, adding that a "general sense of disarray continues" and flagging that net debt rose to a new peak of over $45 billion.

On the plus side, Boeing said it submitted a certification plan to U.S. air-safety regulators in a step toward resuming deliveries of its 787 Dreamliner, halted for nearly a year by inspections and repairs in an industrial headache costing about $5.5 billion.

The 787 Dreamliner, along with the 737 MAX, are vital to the financial health of Boeing, which is trying to bounce back from successive crises.

It has been producing the 787 jets at a low rate while it undertakes inspections and repairs for structural flaws amid intense regulatory scrutiny.

Boeing has "completed the required work on initial airplanes and is conducting check flights", Chief Executive Dave Calhoun told employees in a memo on Wednesday, a development that should cheer airlines that have cut back on flying long routes due to delivery delays.

Calhoun did not specify when Boeing would resume 787 deliveries. Reuters reported last week it had advised key airlines and parts suppliers that the deliveries would resume in the second half of this year.

Boeing also confirmed reports of a delay in handing over the first 777X jet to 2025, but said it remained confident in the program.

Calhoun said the halt in 777-9 production was based on a longer safety certification timeline, a risk reported by Reuters in February.

He said the pause would help minimize inventory and the number of jets requiring retrofits, while it adds to freighter capacity with a newly launched cargo spinoff of the 777X, the world's largest twin-engine passenger plane.

"We are concerned that this delay (in 777X delivery) may allow airlines to cancel without penalty," Citi Research analyst Charles Armitage said.

Reuters reported last month that the Federal Aviation Administration had warned Boeing that existing certification schedules for the 737 MAX 10 and 777X were "outdated and no longer reflect the program activities."

The planemaker said in its first-quarter earnings report that it was on track to generate positive cash flow for 2022 as it ramps up deliveries of 737 MAX aircraft.

It reported a quarterly core loss per share of $2.75, compared with a loss of $1.53 per share a year ago. Revenue fell to $13.99 billion from $15.22 billion.

Like others across the aerospace industry, Boeing is grappling with supply chain shortages, inflation and fallout from the coronavirus pandemic and war in Ukraine.

It booked a $660 million charge in the quarter on its VC-25B - commonly known as Air Force One - due to higher supplier costs and technical problems and schedule delays.

It recorded $367 million in charges for its T-7A Red Hawk trainer jet due to inflation, supply chain issues and impacts related to the pandemic.

It booked pre-tax charges of $212 million due to impacts of the war in Ukraine and international sanctions against Russia, which pose risks to materials supply and aircraft orders.

"This was another dreadful quarter from Boeing," Vertical Research Partners analyst Rob Stallard told clients. "And what we think will really worry investors is that we keep getting MORE bad news."

(Reporting by Eric M. Johnson in Seattle and Abhijith Ganapavaram in Bengaluru; Editing by Arun Koyyur, Bernadette Baum and Nick Zieminski)