AmerisourceBergen Corp. has signed a definitive agreement to acquire World Courier Group, Inc., a privately held global specialty transportation and logistics provider, for $520 million in cash. The transaction, subject to customary closing conditions, is expected to close in 3Q12.   World Courier provides transportation, storage and distribution services for global biopharmaceutical clinical trials as well as other end markets. It will become a new operating segment within AmerisourceBergen. Th...