Amerisource Bergen (ABC -6.5%) shares sink in the wake of Express Scripts (ESRX +5.3%) agreeing...

|By:, SA News Editor

Amerisource Bergen (ABC -6.5%) shares sink in the wake of Express Scripts (ESRX +5.3%) agreeing to buy Medco (MHS +14.7%). Medco is ABC's biggest client, representing 18% of company revenues in 2010. While the Medco contract goes through March 2013, its loss could cause a decline of $0.15/share in ABC's EPS, analysts say.