Senior Member
Store brands are cheaper. Whereas, ‘national brands’ are those that are available everywhere.

Can sentences be seperated nothwithstanding the use of 'whereas'?
  • No you should not substitute notwithstanding for whereas.

    whereas = while on the contrary
    notwithstanding = in spite of

    His question is lightly different, as far as I understand. He is asking whether it is OK to use "whereas" at the beginning of an independent second sentence or to make it a conjunction between the two clauses of one sentence. I would opt for the latter.