King of Prussia, Pa.—GSI Commerce has signed a definitive agreement to acquire Accretive Commerce for $97.5 million in cash. Both companies provide e-commerce services. The deal, which is expected to close in the next two months, will expand GSI’s partner base to nearly 80 companies. Existing partners are primarily in the apparel, home, health, beauty and specialty foods markets. Accretive Commerce, founded in 1995, offers e-commerce technology, customer care and fulfillment services.