CHICAGO — The National Labor Relations Board said it will issue a decision Friday on labor-practice complaints that have been filed nationwide against McDonald’s and its franchisees.

The details of the decision have not been announced by the labor board. But the group organizing fast-food workers, known as Fight for $15, said the NLRB will designate McDonald’s as a joint employer.

Such a decision would increase the fast-food giant’s responsibility in labor cases. McDonald’s could not be immediately reached for comment.

McDonald’s has long maintained that its franchisees are independent owner-operators who set their own policies, including wages, while adhering to corporate standards in areas such as food preparation and restaurant design.

About 90 percent of McDonald’s U.S. restaurants are owned by franchisees. But the company is facing increasing pressure from organized labor and worker groups seeking higher wages, among other benefits.

The Fight for 15 movement, which aims to raise wages at fast-food restaurants to $15 an hour, has been promoted as a push for industry workers in general. Even so, McDonald’s is the main target of many public actions in the effort. Organizers, backed by the Service Employees International Union, also hope to create a fast-food workers’ union.

McDonald’s workers have filed dozens of cases with the NLRB since November 2012, when organized protests against the fast-food industry began in New York.

In July, the NLRB said in a preliminary decision that 43 of those cases had merit and that McDonald’s could be considered by the regional directors as a joint employer in those cases.