Change is an inevitable part of life, but it can be particularly disruptive when it comes to company leadership. With a new CEO comes a new set of priorities, a new way of doing things and a new perspective on what the company needs to do to remain competitive in its industry. Not all CEO transitions are traumatic or even transformative, but there is always that risk. While investors have had reason to expect a change in the CEO office at Apple (Nasdaq:AAPL) for some time, these other companies are likely to face transitions of their own in the not-so-distant future.

TUTORIAL: Financial Careers

1. Berkshire Hathaway
It is difficult to find a more obvious example of a company that is not only facing the likelihood of a near-term CEO change, but also one that will fundamentally impact how the business operates. The current CEO and chairman, Warren Buffett, has shifted his position on succession a few times over the years, and currently it is expected that the investment functions that garner so much attention will likely be split among multiple people. Though Berkshire has an excellent roster of operating units, a change in leadership here is going to significantly alter how business is done. At present, Berkshire Hathaway can do things quickly and effectively in large part because Warren Buffett is Warren Buffett - and a handshake deal with him goes a long way with most people.

2. & 3. Cubic and Tootsie Roll
If Buffett's age (81 years old) makes him an obvious candidate for a list of CEOs likely near the end of their tenure, what then of Cubic (NYSE:CUB) CEO Walter Zable (95 years old) or Tootsie Roll CEO Melvin Gordon (91 years old)? While Tootsie Roll's stock has not lapped the S&P 500 like Cubic's has, both companies have significant insider ownership and that ownership almost certainly has played a role in the long tenure of the current CEOs. Either company would make a logical acquisition target within its industry and the CEO transition process might spur such a move - particularly if the current CEO's descendants are not interested in replicating that long tenure at the top. (Make sure you assess whether a CEO has a stake in doing a good job for you. For more, see A Guide To CEO Compensation.)

4. Marriott
A relative youngin' by the standards of this list, Marriott's (NYSE:MAR) J.W. Marriott (79 years old) continues to run the company his father famously began in 1927 as (indirectly) a root beer stand. While there had been speculation over the years as to whether another Marriott would take the reins of the company, the company named COO Arne Sorenson as the eventual successor back in 2009. Having been with the company for some time, it would stand to reason that the transition to Sorenson won't be overly dramatic.

5. News Corp
Rupert Murdoch has spent much of his career as CEO of News Corp (NYSE:NWS) in the news, and not often in the most favorable light. To call Murdoch "feisty" would be a gross understatement, but it has powered the rise of his company from the operator of a daily newspaper in Adelaide to one of the true global media and news giants. Succession has been a hot topic at News Corp before, and the recent phone hacking scandal has brought the issue to a simmer once again. Whoever replaces Rupert Murdoch at News Corp, it is hard to imagine that person will have the same relentless drive and ambition that was fueled by rising out of Australia's surprisingly rough-and-tumble media market.

6. McDonald's
(NYSE:MCD) and Johnson & Johnson (NYSE:JNJ) are interesting case studies not because their CEOs are all that advanced in years, but for how they may reflect on normal corporate policies and the drawbacks of them. Weldon is not especially old but his career as JNJ CEO has been marred not only by recent product quality debacles, but also a string of largely unsuccessful acquisitions. The question that may be asked is whether the board is truly happy with his performance or whether the board simply believes they can wait it out, encourage Weldon to retire, and avoid a potentially contentious and expensive process of forcing a CEO to resign.

7. Johnson & Johnson

McDonald's is more of the opposite side of the coin. Jim Skinner has done a very commendable job as CEO since 2004, playing a major role in turning around a huge business that was once thought doomed to sluggish growth and competitive attrition. That said, many large companies (those that make up the S&P 500, for instance) have policies of varying levels of formality that "encourage" CEO's to retire at age 65. One of the arguments in favor of these policies has been that it fosters more competition and ambition in upper management if they believe they have a shot to become CEO. On the other hand, truly excellent managers are rare and it would be a shame to see a CEO of Skinner's credentials and demonstrated abilities be encouraged to leave any sooner than he desires.

Inevitable, But Not Always Easy
These are certainly not the only companies with CEOs whose age makes them prime candidates for transitions in the next few years. Other well-known companies like Forest Labs, M&T Bank, and Costco would not be out of place here either. While there is no certainty as to exactly when these men will retire, it is certain that their companies will one day find that they must hire a new CEO and find a new path after what in many cases has been decades of one person's vision and style. Given how hard it is to find good management in general and how hard it can be to follow in the footsteps of a legendary CEO, shareholders and employees of these companies could be looking at some significant changes in the years to come. (For related reading, see 6 Steps To Successfully Switching Financial Careers.)

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