Parties in a supply chain, being independent firms, have private information about various aspects of the business not normally available to other parties. We consider a market where customers need to buy two complementary goods as mixed bundle, offered by two separate firms. The demand for each firm is dependent on the pricing strategy of both firms, which, in turn, depends on the quantities offered as per their own forecasts. We present a profit maximization model to obtain optimal strategies for a firm making decisions under information asymmetry. The model follows a simultaneously played Bertrand type game. We contrast and compare three scenarios: (1) when forecast information is asymmetric between the firms; (2) when forecast information is shared between the firms; and (3) when the firms form a strategic alliance.