• Boeing's CEO said the company has paused deliveries of new 737 Max planes because of electrical problems on some the jets.
• The company disclosed the problems earlier this year but the FAA has not yet approved a fix as the issue has taken longer than expected.
• The 737 Max was grounded for nearly two years after two fatal crashes.

Boeing on Wednesday said it has paused deliveries of its 737 Max after an electrical issue grounded more than 100 of the planes worldwide earlier this month.

The problem is the latest to impact the planes, which were grounded for most of 2019 and 2020 after two fatal crashes killed 346 people. Boeing had resumed deliveries of the jets, its bestselling aircraft, late last year after regulators approved a number of fixes after the crashes.

A final fix for the planes has taken longer than originally expected and comes as airlines are gearing up for a busy summer travel season after a pandemic-devastated 2020. CEO Dave Calhoun told CNBC earlier Wednesday that he expected to finalize the repair instructions "in relatively short order" but did not provide an exact date. The Federal Aviation Administration, which would approve the fixes, said it is "continuing to work closely with Boeing on this issue."

A fix for the electrical issues will likely take just a few days per airplane, Calhoun said.

He said on a quarterly call that the new pause in Max deliveries to airlines "will make our April deliveries very light."

"At this time, we expect to catch up on deliveries over the balance of the year," Calhoun said.

Boeing shares were down more than 3% in midday trading after the company reported a wider-than-expected loss.