WASHINGTON (AP) — The Pentagon's inspector general has formally opened an investigation into a watchdog group's allegations that acting Defense Secretary Patrick Shanahan has used his office to promote his former employer, Boeing Co.

Citizens for Responsibility and Ethics in Washington filed an ethics complaint with the Pentagon's inspector general a week ago, alleging that Shanahan has appeared to make statements promoting Boeing and disparaging competitors, such as Lockheed Martin.

Shanahan, who was traveling with President Donald Trump to Ohio on Wednesday, spent more than 30 years at Boein...