Nissan Motor Co. has taken the unusual step of agreeing to have its affiliated car dealers sell auto insurance provided exclusively by Sompo Japan Insurance Inc. and Millea Holdings Inc., according to company sources.

Car dealers in Japan usually offer auto insurance from several companies.

Under the agreement, the two nonlife insurance groups and Nissan will jointly develop auto insurance products that combine new customized services. The new products will be sold under the Nissan brand at its dealerships, the sources said.