Thoresen was appointed by a panel of the ABI Board headed by ABI chairman, Tim Breedon, following an external recruitment process lead by Odgers Berndtson.
Breedon said: "Otto is a leading industry executive who will bring strong leadership and proven industry expertise to the ABI's work. He will have credibility representing the industry with the first hand-knowledge that comes from running a business in the current challenging regulatory and business climate."
Thoresen was the unanimous choice of the ABI board and was chosen from a shortlist of five candidates.
Breedon added: "I am grateful to Maggie Craig for her hard work as Acting Director General over the last eight months. She has devoted characteristic energy and skill to keeping the ABI moving forward and will hand the ABI over to Otto in strong shape for the challenges ahead."
Thoresen said: "I am excited about taking on this challenge and representing all parts of the insurance industry at this critical time. This is an industry I care passionately about and I will relish the opportunity to engage in crucially important debates with governments, regulators, customers and stakeholders. The insurance industry is facing very significant changes over the next few years and it will be vital that we punch our weight and contribute all we can to the challenges facing us.
"Insurance has a key role to play in building and sustaining a healthy society. It is a vital product for most people but as an industry we still have much to do if we are to be completely customer-focused. The challenges are not necessarily the same for the general and life sectors but we know as insurers that we have to build on the progress of the last few years and always be on the side of our customers.
"The ABI is a strong trade body which I know well from my six years on its board, most recently as a deputy chairman and audit committee chairman. Its principal strength as an organisation is its close relationship with its members and I intend to develop this still further as director general, especially with those sectors of the membership I have been less involved with during my career in insurance."
