$1.8 billion Ambac Financial Group appointed Gregory Raab as chief risk officer. He will succeed David Wallis, who was promoted to president and chief executive of the company in October.

In his new role, Raab will manage Ambac’s $430 billion of net insured par outstanding and make key decisions involving risk management and loss mitigation. Ambac has been hit with financial-guarantee losses, and provisions soared in the fourth quarter.

Raab, who has 20 years of experience in strategy development, previously worked as a chief risk officer for General Electric’s structured finance, public finance, and capital markets group.