(b) 6. A "service supplied in the exercise of governmental authority" means any service which is supplied neither on a commercial basis, nor in competition with one or more service suppliers. Nothing in this Protocol shall be construed to prevent a State Party from adopting and implementing measures aimed at ensuring universal access to essential services. PART TWO GENERAL OBLIGATIONS ARTICLE4 Most Favoured Nation Treabnent 1. Upon entry into force of this Protocol, with respect to any measure covered by the protocol, each State Party shall accord immediately and unconditionally to services and service suppliers of any other State Party treatment no less favourable than it accords to like services and service suppliers of any other State Party or Third Country. 2. Notwithstanding paragraph 1, two or more State Parties may conduct negotiations and agree to liberalise trade in services for specific sectors or sub-sectors in accordance with the objectives in this Protocol. Other State Parties shall be afforded reasonable opportunity to negotiate the preferences granted therein on a reciprocal basis. 3. Nothing in this Protocol shall prevent a State Party from entering into new preferential agreements with third countries in accordance with Article V of GATS provided such agreements do not impede or frustrate the objectives of this Protocol. Prior to negotiating such an agreement, a State Party shall duly inform the other State Parties of its intention to do so and shall afford reasonable opportunity to the other State Parties to negotiate the preferences granted therein on a reciprocal basis. 4. Nothing in this Protocol shall prevent a State Party from maintaining any preferential agreement entered into with a third party, prior to the adoption of this · Protocol. A State Party shall afford reasonable opportunity to the other State Parties to negotiate the preferences granted therein on a reciprocal basis. 5. A State Party may maintain a measure which is inconsistent with paragraph 1, provided it is listed in the Most Favoured Nation (MFN) exemption list. The agreed list of MFN exemptions shall be annexed to this Protocol. The TNF Services shall regularly review MFN exemptions, with a view to determining which MFN exemptions can be eliminated. 6