Termination before completion

You appear to understand FIDIC's provisions, as summarised at the top of page 41 of the Red Book Guide: "It should be noted that ... the effect of ... [1.1(a)(iv)] is to prevent the Employer from changing the Engineer without the consent of the Contractor." In effect, provided the legal person defined as "Engineer" continues to exist, such legal person continues to be the Engineer for the purposes of the Contract, and the Employer has no power to name someone else as Engineer. By "continues to exist", we mean does not (as a natural person) die, or is not (as a company) dissolved. FIDIC cannot give specific advice in respect to the actions a party should take, and only undertakes to clarify aspects of its own provisions. You do not seem to need such clarification, but may need to obtain advice from a lawyer with expert knowledge of construction law.There is always a possibility that some aspect of the situation (which you have not mentioned) would entitle the Employer to replace the Engineer under the law governing the Contract. For FIDIC, it seems that you should first decide whether the replacement "Engineer" is acceptable as such because, if not, you could inform the Employer accordingly and seek to resolve the matter before it escalates into a major dispute. - See more at: http://fidic.org/node/911#sthash.oe3rtNzJ.dpuf