It's unrealistic to continue operating the business while selling off, piece by piece, the real estate the business depends on.
Literal
Business [object-を] continue-[while-ながら], business [subject-が] relies-on-[continuous-ている] real-estate [object-を] sell-off-piecemeal-[continuing-ていく] [thing-こと] [etc-など] unrealistic is-[explanatory-のだ].
Business/editorial reasoning. 切り売り ('piecemeal selling, selling off in pieces') is a noun-form compound from 切る ('cut') + 売る ('sell'), describing the gradual divestment of assets. 依拠する ('to rely on, to depend on') is a formal verb, typically with ~に. 非現実的 ('unrealistic') uses the negating prefix 非 + 現実的 ('realistic'). ~など ('things like, such as') softens and generalizes.