In a deal valued at $318 million, South Portland-based Wright Express has purchased Australian Retail Decisions to expand its international business of fleet and prepaid cards.

The acquisition includes two leading products: ReD Fuel, a fuel card accepted at about 90 percent of Australian fuel retailers, and ReD Prepaid, a prepaid card with approxiamtely 60 percent market share in Australia.

These products generated $61.4 million (Australian currency) in revenue.

Wright Express is an information management and payment processing company for vehicle fleets. The company’s charge cards are used for the fueling and maintenance of about 4.6 million vehicles.