Heat oven to 350°F. Trim fat from pork. Place pork in 13x9-inch glass baking dish. Sprinkle with salt and pepper.
In 10-inch skillet, heat preserves, sherry, rosemary and garlic over medium heat, stirring frequently, until thickened. If necessary, mash apricot pieces with fork into small pieces. Spoon 1/4 cup apricot mixture onto pork (reserve remaining apricot mixture). Insert meat thermometer so tip is in center of thickest part of pork.
Bake uncovered 1 hour 15 minutes to 1 hour 30 minutes or until thermometer reads 155°F. Cover pork with foil; let stand 15 to 20 minutes or until thermometer reads 160°F. (Temperature will continue to rise about 5°F, and pork will be easier to carve.) Cut pork into slices. Heat remaining apricot mixture; serve with pork.