Our Team

Since its incorporation in early 2006 Wimsure Underwriting has grown to a team of 5 people, all of whom are intrinsic to the inner workings of a successful Underwriting agency.

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Mark Williams

Managing Director

Mark has been in the insurance market for 29 years. Before the foundation of Williams Insurance Group in 2003, which houses Wimsure Underwriting Ltd, Mark was a senior underwriting manager for Professional liability lines spanning a period of over 10 years in the London market.  

His career commenced in 1985 as an International Lloyds placing broker and soon assumed responsibilities in the early  professional Indemnity market. In 1992 he became a London market underwriter in PI lines with positions in RSA as underwriting manager, class manager on a Lloyds syndicates, and set up the trading box in Lloyds for Axa Reinsurance prior to the set up of his own company.

Direct Dial - 0203 058 1090
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Marguerite Navin-John


Meg joined Wimsure Underwriting in 2007 having previously worked for 15 years as a broker and Associate Director for the Financial and Insurance broking sectors. She has been an integral part of the growth and development of the company and has courted many successful broker relationships. This has seen her promoted to Director with responsibility for managing the underwriting team and assisting with the overall operation and control of Wimsure.

Direct Dial - 0203 058 1094

Agne Zemaityte


Agne joined Wimsure Underwriting in 2011 as an Assistant Underwriter. Agne is a valued member of the team and is committed to ensuring both new and existing brokers continue to receive a professional and friendly service.

Direct Dial - 0203 058 1092

Alicja Wojtaszek


Alicja joined Wimsure in 2012 and worked her way through to the Underwriter position. She is also the Company Administrator and runs Finance with the Managing Director

Direct Dial - 0203 058 0844

Hans Sherman


Hans has over 20 years working in the Financial Lines (D&O) market. Hans started his career at AIG in the New York Regional Office working in the Middle Market team (Private, Not for Profit, and Public Companies under $5bln market capitalisation). Hans continued to work for AIG in Chicago, New York, Frankfurt, and London in various roles within management liability, always with a focus on new business/portfolio development.

In 2010 Hans left AIG for Starr Companies and Lloyds Syndicate 1919, working to establish their first Management Liability book and creation of a Management Liability consortium, that included Barbican Insurance – where Hans continued his work from 2016 till 2019.  

Hans is a graduate of the University of Kansas and spent 4 years in the United States Marine Corp.

Direct Dial - 0203 058 1091


Get In Touch


6 Lloyd's Avenue, London, EC3N 3AX


0203 058 1090


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