(Reuters) - Boeing Co shares fell by more than 2.2 percent early on Monday, after a pair of newspaper reports over the weekend raised more questions about the certification process for its 737 MAX jets before two recent deadly crashes.
A Wall Street Journal report on Sunday said that the U.S. Transportation Department was probing the Federal Aviation Administration's (FAA) approval of the 737 MAX and in particular its anti-stall (MCAS) system.
The Seattle Times separately reported that Boeing's safety analysis of a new flight control system on 737 MAX jets had several crucial flaws.
Shares of the company have declined about 10 percent since the March 10 Ethiopian crash that killed 157 people, wiping nearly $25 billion (18.9 billion pounds) off its market capitalisation, according to Refinitiv data.
Ethiopia said on Sunday that the crash of the Ethiopian Airlines plane had "clear similarities" with October's Lion Air crash.
The U.S. Transportation Department's inquiry, which was launched in the wake of the accident in October that killed 189 people, has warned two FAA offices to safeguard computer files, the WSJ reported.
Last Monday, Boeing said it would deploy a software upgrade to the 737 MAX 8, hours after the FAA said it would mandate "design changes" in the aircraft by April.
(Reporting by Sanjana Shivdas in Bengaluru; Editing Patrick Graham, Bernard Orr)