It's really hard to become more lean without losing some strength. It takes a very strict diet. I've been working on getting bigger/stronger and I've lost some definition. Without steroids or an incredibly strict diet, it seems you have to pick one or the other.
You'll still be strong, just not AS strong. You will have more endurance and a better appearance though. Ramp up the cardio and keep the lifting. Cut the calories a bit. You'll see results. I'm planning to boost my cardio as well and just accept the strength loss.