Just weeks after his inauguration, President Trump toured Boeing’s factory in North Charleston, S.C., holding a rally with workers, admiring a new 787 Dreamliner and calling on the company to bring down the cost of new Air Force One planes.

But Boeing wanted something from Mr. Trump, too.

During a private conversation at the event, Boeing’s chief executive, Dennis A. Muilenburg, talked to Mr. Trump about a long-running trade dispute between the United States and the European Union that had its roots in the pitched rivalry between Boeing and Airbus, according to three people familiar with the meeting, who spoke on the condition of anonymity to discuss a delicate matter.

The case, which centered on subsidies that Europe provides Airbus, had been working its way through the World Trade Organization for years, but an end was finally in sight. In the event that it was settled on Mr. Trump’s watch, Mr. Muilenburg urged the president to enforce the ruling, which would mean levying tariffs on European goods.

On Wednesday, Boeing got its wish. After an announcement by the World Trade Organization, the Trump administration said it would tax as much as $7.5 billion of European exports annually.