Actavis PLC said today it plans to replace most of the top executives at Allergan Inc. with its own personnel when its $68 billion acquisition of the Irvine-based drug maker closes next year.

Allergan President Douglas Ingram will remain and serve as a special advisor to Actavis Chief Executive Brent Saunders, Actavis said in a statement.

Actavis spokesman David Belian told Bloomberg that current Allergan Chief Executive David Pyott’s role has not yet been determined although it was possible that Pyott could join Actavis’ board after the deal closes.

Allergan shares were down 1% to a market value of $61.9 billion. Actavis shares were down 1% to a market value of $68.9 billion.