By Anabela Reis - Oct 2, 2013 4:37 PM ET
Oi SA, Brazil's biggest phone company, agreed to merge with Portugal Telecom SGPS SA to create a trans-Atlantic carrier whose 100 million customers make it more competitive against Telefonica SA and America Movil SAB.
Shareholders of Oi will own the majority of the combined company after the transaction, which requires the Rio de Janeiro-based carrier to sell new stock for as much as 2.7 billion euros ($3.7 billion). Its shares soared as much as 12 percent in Sao Paulo. Portugal Telecom, whose investors will get 38 percent of the new Brazil-based entity, jumped as much as 23 percent in Lisbon.