Boeing 737 MAX aircraft, including two 737 MAX 8 aircraft bearing the logo of China Southern Airlines, third from left and another seen at right, are parked at a Boeing production facility in Renton, Washington, U.S. March 11, 2019. REUTERS/David Ryder

SEATTLE (Reuters) - Boeing Co said on Friday its software upgrade for the grounded 737 MAX jetliner will be rolled out in the coming weeks, and that its timeline for deploying the upgrade has not changed.

Boeing has been working on a software upgrade for an anti-stall system and pilot displays on its fastest-selling jetliner in the wake of the deadly Lion Air crash in Indonesia in October. Similarities between the flight path in the Lion Air incident and Sunday’s Ethiopian Airlines crash have raised fresh questions about the system.

Boeing said on Monday it has been working closely with the U.S. Federal Aviation Administration on development, planning and certification of the software upgrade, and it will be deployed across the 737 MAX fleet in the coming weeks.

The FAA expects to approve these design changes no later than April 2019, it has said.

Boeing shares rose as much as 1.5 percent in midday trading, reversing course from losses of about 1.5 percent earlier in the session.