Hiscox has acquired the renewal rights to an $8m (£4.45m) book of fine art policies from Ascot.
The move follows Ascot's decision to scale down its fine art underwriting following the departure of the insurer's fine art underwriter Annabel Fell-Clark to AXA Art last month.
Ascot business development manager Torquil Mclusky said: "We are scaling back our fine art underwriting quite considerably.
"Going forward we will continue to write some fine art in our specie account underwritten by Gary Tredgett."
Hiscox chief executive Bronek Masojada said: "As the leading specialist fine art and high net worth insurer in Europe, we are pleased to be able to offer a solution and our expertise to Ascot's clients and brokers.
"This deal reflects our drive to further grow our fine art and high net worth retail business."
The fine art policies were until now underwritten through Syndicate 1414 by Ascot. The agreement was effective from 18 August.