'Sectorial' passes both US and UK spellcheck on Word (in addition to sounding better), whereas 'Sectoral' doesn't. You can also use 'sector' alone as an adjective, or compounds like 'sector-based' to avoid ambiguity.

What is the definition of sectoral?

Sectoral means relating to the various economic sectors of a society or to a particular economic sector. [technical] ... sectoral differences within social classes. 'sectoral'

Is Sectorially a word?

sec·to′ri·al (-tôr′ē-əl) adj.