See FAR Sec. 25.121 - Climb: One-engine-inoperative.

"Take off, Landing gear retracted.....the steady gradient of climb may not be less than 2.4 percent for two engine airplanes, 2.7 percent for three engine airplanes, and 3.0 percent for four engine airplanes at V2..."

I really need to learn how to do the cut and paste thing from other web sites.

Joe