Ambac sues Puerto Rico highway agency over toll road deal

(Reuters) - Ambac Financial Group Inc., a bond insurer with significant exposure to Puerto Rico, on Wednesday said it has sued the island's highway authority to block a lease extension for the operation of two toll roads in the U.S. territory.

Ambac said the 10-year lease extension, granted last month, could divert $115 million from the cash-strapped Puerto Rico Highways and Transportation Authority, or PRHTA, to Autopistas Metropolitanas de Puerto Rico LLC, a joint venture of Spain's Abertis and Goldman Sachs Infrastructure Partners.

In its suit filed in the U.S. District Court for the District of Puerto Rico, Ambac seeks the appointment of an interim receiver for PRHTA.

Puerto Rico faces $70 billion in total debt, as well as economy-killing emigration and a staggering 45 percent poverty rate.

(Reporting By Dan Burns; Editing by Chizu Nomiyama)