Season steaks with salt. Press pepper on surfaces.
Heat oil in large heavy skillet over high heat.
Add steaks. Lower heat to medium; cook, turning once, 4 minutes per side for rare, 6 minutes per side for medium-rare, and 8 minutes per side for well-done.
Remove to warm platter; keep warm.
Add onion to skillet; cook until browned, stirring, 2 minutes.
Add half the rosemary, half the garlic and cook, stirring, 20 seconds.
Add wine. Increase heat to high; boil vigorously 2 minutes.
Add broth, sugar and meat juices that have collected on platter. Boil 10 minutes more or until liquid is reduced by half, about 1 cup.