Readable Chinese, please.

I'm now updating a Chinese JVC against its English version. The original Chinese translation was supposed to have been proofread by some lawyers, who, presumably were Chinese natives. However, I do not feel comfortable for the "set" Chinese wordings. Here we go:

PPP will not cease to directly or indirectly wholly own the equity and voting rights of Party B during the duration of this Contract except with the prior written consent of Party A.

除非经甲方事先书面同意，否则PPP在本合同有效期内不得停止直接或间接地拥有乙方全部股权和投票权.

What do you guys think of the translation? I'm not being picky, right? It STICKS to the English PERFECTLY but it does not sound Chinese. My draft version goes this way:

除非经甲方事先书面同意，否则,在本合同有效期内,PPP须始终直接或间接地拥有乙方的全部股权和投票权。

A slimmer one:
在本合同有效期内,非经甲方事先书面同意，PPP须始终直接或间接地拥有乙方的全部股权和投票权。