The corporate spinoff is in. Less than two weeks into the new year, conglomerate ITT Corp. (NYSE: ITT) and Marathon Oil (NYSE: MRO) have announced plans to split their companies into multiple publicly traded entities.

ITT will be divided into three companies -- a defense business, a water technology business, and an engineered products business. Prior to its announcement, the company traded at only 11 times 2011 earnings estimates, reflecting investor concerns about defense spending cuts and their impact on the company's largest business. ITT stock jumped more than 20% upon the announcement.

Marathon Oil will split into two companies -- one handling the upstream operations (exploration and production) and one focusing on pipelines, refining and marketing, and the Speedway gas station chain. The stock bounced as much as 11% in today's trading.

ITT's and Marathon's announcements closely follow a similar one from Fortune Brands (NYSE: FO), the maker of items -- such as bourbon, kitchen cabinets, and golf balls -- that have next to nothing in common with each other, and the long-awaited completion of Motorola's split into Motorola Mobility (NYSE: MMI) and Motorola Solutions (NYSE: MSI).

What's driving this trend? Based on what we've seen this week, it's certainly a good way to move your stock price quickly. The involvement of activist investors has likely played a role in nudging some CEOs and their boards toward the decision.

Looking beyond the headlines and initial stock price bounce, spinoffs are a good place for investors to look for opportunities. As Joel Greenblatt explains in his book You Can Be A Stock Market Genius, spinoffs generally outperform the market, and the cumbersome and time-consuming process of actually completing the process gives investors ample time to assess the prospects of each new business entity that results.

So which companies might be next in line to make a spinoff announcement? Conglomerates United Technologies, Honeywell, Danaher, and, of course, the granddaddy of them all, General Electric, come to mind, but as Motorola and Marathon Oil show, they don't have to be traditional conglomerates. Sound off in the comments section below to let us know which company you think will next do the spinoff dance.

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