American Olympians could find it easier to promote products and sponsors during the Games after the United States Olympic and Paralympic Committee loosened some of its strict marketing rules on Tuesday.

For years, athletes have chafed about one such guideline, Rule 40 of the Olympic Charter, which sharply restricts what they can say and do with their sponsors immediately before and during the Games. Many athletes call it a “gag rule” that curtails their freedom of speech and unfairly sidelines the sponsors who bankrolled and supported their training, sometimes for years, at the moment of highest visibility. Olympic officials have long argued that the rule was necessary to protect the interests of the smaller group of official partners who spend millions of dollars to be associated with the Games.

While the International Olympic Committee created Rule 40, it left interpretation of it to the national committees. In recent years, a German government body weakened the I.O.C.’s authority when it declared Rule 40 was “too far-reaching” and said German athletes no longer had to abide by it. But many national Olympic committees, including the one in the United States, had stuck by a strict reading in the face of ambush marketing campaigns and protests by its own athletes.

At least one, the two-time Olympian Nick Symmonds, even cited the restrictions as a motivation for taking an early retirement.