Complex sentence: The sale of Atlantic Records activated a clause in the distribution agreement with Stax Records calling for renegotiation of the distribution deal and at this point the Stax partners discovered that the deal gave Atlantic ownership of all the Stax recordings Atlantic distributed.
Split into simpler sentences: The sale of Atlantic Records activated a clause in the distribution agreement with Stax Records calling for renegotiation of the distribution deal. The Stax partners discovered that the deal gave Atlantic ownership of the Stax recordings Atlantic distributed.