WASHINGTON — Federal regulators are moving toward making it easier for shareholders to nominate directors of public companies, a change sought by investor advocates that is already sparking protest from the nation’s biggest business lobby.

The action expected from the Securities and Exchange Commission on Wednesday will allow groups that own at least 3 percent of a company’s stock to put their nominees for board seats on the annual proxy ballot sent to all shareholders.

SEC Chairman Mary Schapiro says the change is “a matter of fairness and accountability.”

But a U.S. Chamber of Commerce official calls it “a giant step backwards for average investors” and said the organization will fight it “using every method available.”