Genentech Chairman Arthur D. Levinson on Monday announced his resignation from Google’s Board of Directors, choosing instead to remain on Apple’s board. A member of Google’s board since 2004, Levinson is the last tie between Apple and Google after Eric Schmidt resigned his Apple seat earlier this year.

Google CEO and Chairman Eric Schmidt said Levinson was a “key part of Google’s success these past five years, offering unvarnished advice and vital counsel on every big issue and opportunity Google has faced.”

Of course, Google and Apple have been at odds with each other for months now. The two companies have increasingly been encroaching on the others turf, which lead to Schmidt’s resignation from Apple’s board in August.

Then Google Voice was rejected from the App Store because it duplicated the functions of the iPhone, bringing the FCC into the mix.

While Apple denied the app had been rejected, Google said it was and gave details of conversations between the companies.

In early October Apple purchased mapmaking company Placebase, adding fuel to fire and speculation that the relationship between the two companies is strained.