Apple Inc. (Nasdaq: AAPL) shares plunged on German stock exchanges today after it was reported that Chairman Steve Jobs would take another leave of absence, fuelling worries about the potential length of his absence and the extent of his health issues.

Shares of the tech giant dropped 7.81 percent, 7.64 percent and 6.89 percent, respectively, on the Dusseldorf, Berlin and Hamburg exchanges.

Observers of the U.S. stock markets (which are closed today due to the Martin Luther King Jr. holiday) will clearly keep a close eye on Apple stock performance tomorrow.

In addition, the company will release its fiscal first-quarter earnings tomorrow after the close.