I have a sentence, say:
He has worked in banking industry and manufacturing industry for more than 15 years.
My question is the first "industry" could be omitted? If done, we should use "banking and manufacturing industry" or "banking and manufacturing industries"? Which one is correct.
Yes, you can remove the redundant "industry", but both banking and manufacturing together are two industries, plural. Don't forget the definite article:
He has worked in the banking and manufacturing industries for more than 15 years.
However, in this context "industry" itself is not necessary. By definition, things like "banking" or "manufacturing" or "commerce" or "trade" or "shipping" represent categories of industries. Since these are generic concepts, don't use the definite article:
He has worked in banking and manufacturing for more than 15 years.
