CVS Caremark Corp.'s second-quarter net income jumped 18.4 percent, as new business for its drugstore chain and an expansion of its pharmacy benefits management segment pushed revenue higher.

Its adjusted earnings topped Wall Street estimates, the company raised its forecast for 2012 and CVS shares rose more than 2 percent in premarket trading.

The Woonsocket, R.I., company said a recently settled split between rival drugstore chain Walgreen Co. and Express Scripts Holding Co. sent customers to CVS drugstores, and it aims to keep them. CEO Larry Merlo said the split added between 6.5 million and 7 million prescriptions for his pharmacies in the quarter, and it contributed about 3.5 cents per share to earnings.