Rotterdam based underwriting agency RaetsMarine has been sold to the London based Amlin insurance group, which already has a strong presence in the marine market.

The Raets group was founded in 1993 by former insurance broker Martin Lanting and has been a major success story, diversifying from charterers P&I into providing liability cover for owners, hull and cargo as well as other insurances.

Lanting (60) remained chairman and sole owner of the business, so the Dutch postman’s son who became a Monaco millionaire some years ago to indulge an interest in large yachts and racing Ferrari’s and fast BMWs has done rather well.

Amlin, the company behind Lloyd’s of London syndicate 2001, has been the underwriting security behind the RaetsMarine underwriting agency for a decade so knows the business well.

RaetsMarine, which wrote $105m of premium last year, has a staff of 130 and operations in Paris, London and Singapore as well as Rotterdam.

Lanting gets $25m in cash and a further $25m in Amlin London stock exchange quoted shares when the deal completes this week. There will be a further payment of up to $15m in two years time, depending on the claims ratio achieved by the RaetsMarine’s hull and cargo business for the 2010, 2011 and 2012 underwriting years.

RaetsMarine managing director, Folkert Strengholt, will continue to run the business which will be part of Amlin Netherlands Holding, the business created after Amlin’s 2009 acquisition of Fortis corporate insurance.

“Amlin has ambitious growth plans for our global marine business and this acquisition represents a key part of our coherent international marine strategy,” said Amlin underwriting chief, Simon Beale. “RaetsMarine is an established and well run business and we look forward to building on the opportunities it presents.”

Strengholt also welcomed the deal. “This transaction makes enormous sense, as it will enable us to provide our clients with a broader marine insurance offering and to benefit further from the close working relationship we already have with Amlin,” he added.