LONDON—Jardine Lloyd Thompson Group P.L.C. said Monday that is has signed an agreement with three independent insurance brokers to develop its international network in mainland Europe.

JLT, the world's eighth-largest broker in the latest Business Insurance ranking, said its exclusive agreement is with Detmold, Germany-based Ecclesia Group; Vienna-based GrECo Group; and Paris-based SIACI Saint Honoré, which is known as S2H.

As part of the agreement and subject to regulatory approval, London-based JLT will take a 20% stake in GrECo. JLT already has a 20% stake in S2H and Ecclesia already has a 13.3% stake in GrECo.

Outside Austria, GrECo will rebrand as GrECo JLT, said Rory MacLeay, a London-based partner of Jardine Lloyd Thompson Ltd. and head of the JLT international network.

Mark Drummond-Brady, international chairman of JLT's risk and insurance division, said the arrangement would “increase the gravitas” of JLT's network for its U.S. client base.

While JLT withdrew from U.S. retail business in 2006, it still operates in the wholesale market.

Mr. Drummond-Brady will chair the network's business development forum, which will set targets and plan product development for the network, among other things. The effort will focus on JLT's specialties that include construction, energy, financial services, health care, communications technology, life sciences, transport and aviation, and reinsurance.

JLT will likely extend the network model to other territories, Mr. Drummond-Brady said.

JLT's international network currently is represented in 130 countries.

In 2009, JLT had gross revenues of £620.1 million ($1 billion), S2H had €177 million ($253.4 million), Ecclesia had €142 million ($203.3 million), and GrECo had €58 million ($83 million).