LOS ANGELES (Reuters) - Walt Disney Co, owner of the ABC broadcast network and a suite of cable channels, will stop accepting some junk-food ads on TV programs, radio shows and websites aimed at children, according to sources with knowledge of the plan.

Disney Chief Executive Bob Iger and first lady Michelle Obama plan to make an announcement on Tuesday in Washington, the sources said.

The United States faces an obesity epidemic. Nearly one-third of U.S. children are overweight or obese, and a 2006 Institute of Medicine report said junk food marketing contributed to childhood obesity.

The Disney move follows New York Mayor Michael Bloomberg's announcement last week of a plan to ban sugary drinks larger than 16 ounces (about half a liter) in most restaurants, theaters, delis and vending carts throughout the city.

The ban, also aimed at fighting obesity, would affect drinks equivalent to what McDonald's Corp calls small and has incensed food and beverage makers, many of which have agreed to voluntary nutritional measures.

Disney plans to cut advertising during children's programming on its networks such as ABC and Disney XD or its kid-focused websites for foods that fail to meet minimum nutrition requirements, the sources said.

A Disney spokeswoman declined to comment on Tuesday's announcement.

The media and entertainment conglomerate introduced voluntary guidelines in 2006 that prohibited licensing of Mickey Mouse and other Disney characters for foods that fail to meet minimum nutrition the requirements.

The guidelines set limits on the amount of calories, fat and added sugar for main and side dishes and snacks.

Last year, top U.S. food and drink makers including Kraft Foods, Coca-Cola and Kellogg Co agreed to voluntary nutrition criteria for products advertised to children.