Brenda Barnes, the Chairman and Chief Executive Officer of Sara Lee (SLE) was recently forced to take a medical leave of absence.  Approximately a month after the leave began, the company reported that a stroke was the reason for her departure.  A group of top-level executives have stepped in to guide the company in her absence.  While this event may or may not be material to Sara Lee’s long-term future, the departure of a strong leader, particularly a company founder, can be a meaningful event that shareholders should not take lightly.

One of the best examples of a leader’s departure having a big impact on a company is likely Apple (AAPL).  One of the founding forces of the company, Steve Jobs is virtually synonymous with the company he leads.  That wasn’t the case in 1985, however, when he was forced out of the company because of disagreements about the direction of the computer maker with the CEO (Jobs was Chairman of the Board at the time).  Apple floundered badly after Jobs’ departure and eventually bought his new company, called NeXT, to get him back in the corner office at Apple.  The performance of the company since is nothing short of dramatic, including the launch of the i-pod, i-phone, i-pad, and the i-Tunes media store. 

Clearly Jobs’ vision plays a vital role in Apple’s success.  Having him back at the helm is important to both the performance of the company and its shares, as investors are well aware of how vital his vision is to the company’s future.  That said, Jobs, too, has had health issues that forced him to take a leave of absence.  Such medical concerns have surfaced several times in recent years and, while not appearing to have impacted the company’s performance over the longer term, each time the medical condition has surfaced in the media it has temporarily impacted Apple’s stock price in a negative way. 

There are other companies that have strong leaders who have left only to return when the company they once drove began to flounder.  The list includes such well-known brands as Dell (DELL) and Starbucks (SBUX).  However, there are a number of other companies where charismatic (or not so charismatic, depending on one’s view) leaders are a driving force. 

Berkshire Hathaway’s (BRKB) Warren Buffett, for example, is also viewed as synonymous with the company he leads with Charlie Munger.  Both men are beyond the age where retirement is the norm and illness leading to death is not considered rare or surprising.  The company has a succession plan, though little is disclosed about it.  Investors who own shares of Berkshire need to be cognizant of and comfortable with the succession issue at this company or they risk a nasty surprise when Buffet and/or Munger are no longer with the corporation. 

Larry Ellison of Oracle (ORCL) is another example.  While many criticize Ellison’s management style, he is clearly the driving force of the company he co-founded.  The loss of Ellison, who is also at retirement age, could materially alter the technology company.  Shareholders need to be aware of just how important this one man is to the future of the company and the price of the stock they hold. 

Sumner Redstone of Viacom (VIA) is yet another leader who’s loss could materially alter both the company he leads and its shares.  Often noted as one of the most powerful media magnets, his vision is a major driving force at Viacom.  He is now well into his eighties.  The company is clearly large enough to survive his departure, but the loss of his vision and leadership (which, like Ellison’s, is often criticized) could change forever Viacom’s appeal as an investment.

There are clearly many more companies with charismatic and influential leaders, such as John Chambers of Cisco (CSCO).  While most companies do indeed have “lives” of their own, their driving forces are still the people working within them.  To ignore this fact is a mistake.  These few examples highlight how vital it is for investors to keep this issue in mind when buying shares in a company and act as a warning for shareholders who own the companies at which Jobs, Buffett, Ellison, and Redstone work.