BRUSSELS--Orange SA (ORA.FR) has secured European Union approval for its 3.4 billion euro ($3.87 billion) acquisition of Spanish broadband and cellphone operator Jazztel PLC (JAZ.MC) after agreeing to a package of divestments and network agreements that would help create a new telecoms rival in Spain.

The merger will almost double Orange's market share in broadband Internet access in Spain, leapfrogging Vodafone Group PLC to become the country's second-largest provider in that segment. Both companies trail the market leader, Telefónica SA.