Global companies are looking to emerging markets for growth. Companies in emerging markets are looking for ways into the burgeoning global economy. Alliances can seem the obvious solution for both sides.

For global companies, limitations on foreign ownership make an alliance the only route into some markets. In other markets, alliances provide an appealing way to accelerate entry and reduce the risks and costs of going it alone. The US company Aetna Insurance, for example, recently announced a joint venture with Sul América Seguros, Brazil’s largest insurance company. Aetna is reportedly investing $300 million, with a possible $90 million more to follow, for a 49 percent stake in the joint venture. The aim of the Brazilian-based alliance is to accelerate growth and introduce new products in health, life, and personal insurance and pensions. Aetna contributes expertise in products, information technology, and servicing, while Sul América brings local knowledge, an extensive distribution network and sales system, and its leading market position.

Companies in emerging markets can find the idea of an alliance equally attractive. For those in a position of strength, it can be a powerful vehicle for growth, or a way to leverage low-cost manufacturing or a unique distribution...