No insurance company may cancel, refuse to renew or otherwise terminate a written contractual relationship with any individual insurance producer who has been employed or appointed pursuant to that written contract by an insurance company as a result of any analysis of a loss ratio resulting from claims paid under the provisions of an endorsement for uninsured and underinsured motor vehicle coverage issued pursuant to the provisions of section thirty-one, article six of this chapter, nor may any provision of that contract, including the provisions for compensation therein, operate to deter or discourage the individual insurance producer from selling and writing endorsements for optional uninsured or underinsured motor vehicle coverage.