Oceanair Linhas Aéreas S/A, the Brazilian carrier which operates under licence as Avianca Brasil (O6, Sao Paulo Congonhas), has hired UBS Group AG to advise it on the proposed sale of at least 20% of its stock to an undisclosed firm.

Sources who spoke to Bloomberg on condition of anonymity said the stake is valued at at least USD150 million with the sale process already under way.

In an interview, Oceanair CEO, José Efromovich, said the airline and Colombia's Avianca Holdings SA, whose chairman, German Efromovich, is his brother, were seeking separate international partners despite the long-term goal of merging. Avianca Holdings has hired Bank of America Corp. as an adviser.

Earlier this month, Bloomberg confirmed United Airlines parent United Continental Holdings Inc., Delta Air Lines Inc., and Copa Airlines SA had all made non-binding offers for shares in the Colombian carrier.