AmerisourceBergen Corp., said Monday it had agreed to buy H.D. Smith, which it described as the nation's largest privately-held wholesale drug distributor, for $815 million in cash.

The deal is expected to add slightly to AmeriSourceBergen's earnings per share in the fiscal year that started Oct. 1. Revenue growth in fiscal 2018 is now expected to be in the range of 8 percent to 11 percent, up from 7 percent to 9 percent, the Chesterbrook company said. AmerisourceBergen had net income of $414 million on revenue of $153 billion in the year ended Sept. 30.

"This acquisition also builds upon our foundation and meaningfully expands our support for independent community pharmacies," said Steven H. Collis, chairman and chief executive AmerisourceBergen.

H.D. Smith, founded in 1954, is based in Springfield, Ill. It has 10 distribution centers across the country.