The terms merger and acquisition are frequently used as if they are synonyms, but have different implications. The major difference between a merger and an acquisition is their mode of finance.
Mergers as well as acquisitions involve one or many companies purchasing all or part of another company. A merger is a result of two firms, often of similar size, agreeing to move ahead and exist as a single new company. This sort of action in particular is referred to as a "merger of equals." Mergers are mostly financed by a stock swap. In a stock swap, owners of stock in both companies receive an equivalent measure of stock in the newly formed association. Both companies surrender their stocks and stock of the new company is issued as a replacement. A single administrative section then manages the new union.
On the contrary, when one company takes over another company, it is the buyer who is the sole proprietor. Such deals are an acquisition. In legal terms, the target company ceases to survive. The buyer swallows the company and the buyer's stock continues to be traded. Acquisition refers to two unequal companies becoming one and the mode of financing may involve a cash and debt combination, all cash, stocks or additional equity of the company.
A business deal will be regarded as a merger when CEOs of both companies agree that amalgamation is in for the best interest of both companies. A takeover occurs when the target company does not want to be purchased. Such deals are termed as an acquisition.
Whether the deal results in a merger or an acquisition essentially depends on whether it is friendly or unfriendly and the way it is announced. In other words, the main difference lies in how the purchase is communicated to and received by the target company's board of directors, shareholders and employees.