McDonald's Corp. is introducing a new burger on Friday in participating outlets in Southern California.

The "Big 'n Tasty" burger is a quarter-pound beef patty with tomato, lettuce, onions and a new sauce on a sesame-seed bun. It will cost 99 cents.The introduction follows reports last week that McDonald's planned to make changes in its menu, including improved sauce, after research showed its burgers aren't as tasty as the competition's.

There are more than 500 franchised and company-owned McDonald's restaurants throughout the Southern California area.