McDonald's Corp. has agreed to pay $4 million to the federal government for failing to report more than 400 playground injuries children incurred at its restaurants.

The settlement, which involves climbing equipment no longer found at any of McDonald's 5,000 playgrounds, also sets new, strict reporting standards for the world's largest fast-food chain.

Under the agreement, to be announced at a news conference today, McDonald's has promised to file detailed injury reports on all of its playground equipment with the Consumer Product Safety Commission. The CPSC will then determine whether further investigation is necessary.

Up to now, McDonald's -- and all other companies -- had to report injuries to the commission only when they believed they had a defective product.

The settlement -- the largest penalty ever imposed by the CPSC -- comes just four years after McDonald's settled similar charges with the commission over another piece of playground equipment.

At that time, the company promised to report future playground defects to the CPSC and launched a $5 million safety campaign overseen by the commission.

"I'm absolutely determined that companies that make a commitment to the CPSC must keep those commitments," said CPSC Chairman Ann Brown.

McDonald's spokesman Walt Riker said the settlement resolves a bureaucratic dispute over just how and when the company should report injuries to the government.

"We maintain we didn't do anything wrong, but we decided to have a nice cooperative settlement to close the books," Riker said.

The equipment at issue in the latest dispute is the "Big Mac Climber," a metal jungle gym resembling a hamburger.

The play platform was four feet off the ground but "didn't have means of an egress that was safe," said CPSC's general counsel, Jeff Bromme.

"Kids could fall off, and they did."

Children also hurt themselves climbing up and down its narrow ladder.

The Big Mac was installed on McDonald's playgrounds in the 1970s and '80s. It has been phased out in the '90s in favor of safer plastic equipment.

"It was already on the extinction list" when the company signed its 1995 agreement with the CPSC, Riker said.

Most of the 400 injuries involved falls, with 20 children suffering concussions or skull fractures and 80 children incurring broken bones.