Lawrence, who joins Brunswick in the summer, has been at Munich Re - generally ranked as the world's largest reinsurer, or insurer of insurance firms - for 10 years.
Before this, Lawrence held senior comms roles at asset management firm Allianz Global Investors, General Reinsurance (based in the US), and Bosch, where his various roles included head of comms at its UK subsidiary.
Brunswick Group CEO Susan Gilchrist said: "Christian Lawrence is a recognised communications expert with tremendous experience. We are very pleased that he will be joining us to strengthen our team in Germany, one of our key markets in which we have delivered strong growth in recent years.
"Christian will also further develop our capability to support both German and international clients on cross-border transactions and projects."
London-headquartered Brunswick said its German offices have recently advised on a number of cross-border transactions, including Bayer AG’s $66bn (£52bn) acquisition of Monsanto, the merger of Siemens’ wind power business with Spain’s Gamesa, the acquisition of Krauss Maffei Group by ChemChina, and the takeover of robot maker Kuka by China’s Midea Group.
Brunswick, the world’s ninth biggest PR agency by revenue in 2015 according to PRWeek’s Global Agency Business Report, has offices in 23 countries.