Updated from 11:15 a.m. EST

Fast-food giant McDonald's ( MCD) isn't out of the woods. In fact, it might be traveling deeper into them.

The world's largest restaurant chain issued a profit warning Tuesday for the eighth time in the last nine quarters, as the Dow component struggles to cope with a fierce price competition and challenging economic conditions around the world.

The shares were recently trading down $1.54, or 8.9%, at $15.83 on the New York Stock Exchange .

The Oak Brook, Ill.-based company said it would not meet analysts' or its own financial targets for the fourth quarter and that same-store sales are tracking below plan. McDonald's plans to take a $390 million restructuring charge and post a loss of 5 cents to 6 cents a share in the period. Excluding the charge, the company said it would earn 25 cents to 26 cents a share, short of analysts' consensus estimate of 31 cents a share.

Two months into the quarter, McDonald's said sales at U.S. units open at least a year are down 1.3%, and 1.5% through the first 11 months of the year.

Last month, the company announced it would restructure certain markets, close underperforming restaurants and eliminate jobs in order to pare costs and reallocate resources. Tuesday's profit warning comes two weeks after McDonald's announced the retirement of chairman and chief executive Jack Greenberg after 21 years with the company.