(Adds clarification from Itau that earnings boost is pretax)
By Asher Levine
SAO PAULO, July 4 (Reuters) - Itau Unibanco Holding SA , Brazil's largest nongovernment bank, expects a pretax earnings boost of 1.1 billion reais ($497 million) from the sale of its high-risk corporate insurance portfolio to global insurance company ACE Ltd, according to a Friday securities filing.
ACE will pay 1.515 billion reais in cash for the unit, according to terms of the deal, which was signed on Friday. A later securities filing clarified that the 1.1 billion reais the sale is expected to add to Itau's profit is pretax.
The unit specializes in offering insurance coverage for big corporate projects in high-risk segments such as oil and gas and infrastructure.
ACE said in a separate statement that the transaction is expected to be completed in the first quarter of 2015, adding to earnings immediately. Upon completion, it will make ACE the largest commercial property and casualty insurer in Brazil.
In 2013, the unit had about 2 billion reais in gross premiums written and an 18 percent market share.
The deal, which is subject to contract conditions and regulatory approval, is part of Itau's strategy to focus on mass market insurance policies that are more associated with retail banking, Itau said in an emailed statement.
Brazilian government officials have said they expect policy underwriting in the high-risk and reinsurance segments to grow three times as fast as overall economic growth through 2015. But with economic growth trailing the government's 4.5 percent average target between 2011 and 2014, returns and policy underwriting have suffered.
Preferred shares of Itau Unibanco were unchanged at 31.79 reais in early Sao Paulo trading on Friday. ACE shares did not trade in New York due to the U.S. Fourth of July holiday.
($1=2.2132 Brazilian reais) (Reporting by Asher Levine; Editing by Bernard Orr; and Peter Galloway)