Apple Shares Steady On iPhone Exec's ExitApple Shares Steady On iPhone Exec's Exit

Investors were unfazed by iPhone design chief Mark Papermaster's departure from Apple over the weekend, as the company's stock was flat in early trading Monday. Apple shares were up .22%, to $260.67, moments after the opening bell.

Apple confirmed Sunday that Papermaster was out, but the notoriously secretive vendor did not give an explanation for his leaving.

Many observers are speculating his exit is related to "Antennagate"—an embarrassing incident in which Apple has been forced to give away free cases to iPhone 4 buyers to compensate for the device's buggy antenna.

Apple on July 23rd released a downloadable app that allows iPhone 4 customers to get a free case, or "bumper," that's designed to protect the smartphone from the so-called "grip of death bug" that hinders antenna performance. Apple has said the program may cost it as much as $175 million.

Other reports indicated there was ongoing tension between Papmermaster and Apple CEO Steve Jobs. Before joining Apple early last year, Papermaster spent 25 years in the button downed, blue-suited culture at IBM's suburban New York offices. The suggestion is Papermaster never quite fit in to the more the more freewheeling atmosphere that prevails at Apple headquarters in Cupertino, Calif.

Papermaster's departure from IBM triggered a lawsuit in which Big Blue accused him of violating a non-compete agreement. Under a settlement reached in January, 2009, Papermaster was to check in with IBM if he suspected that any innovations he developed at Apple infringed on confidential or proprietary information he picked up during his years of work at IBM.

Whatever the reason, the events that led to Papermaster's departure appeared to culminate within just the past few days, as SEC records show he received from Apple a sizeable stock distribution, worth about $180,000, as recently as July 30.

Apple said Papermaster's duties as senior VP for Device Engineering will be assumed by Mac hardware chief Bob Mansfield.