Irish budget carrier Ryanair is hoping to firm plans for an operation at Barcelona's main airport, El Prat, by around May in order to begin summer flights.
The airline already serves the Girona and Reus airports outside of the Spanish city, but has been in talks to establish services from the main hub.
Ryanair believes it can transport some 3 million passengers per year from Barcelona.
A spokesman for Ryanair says the airline ideally wants to begin operations from El Prat during the summer and adds that it hopes to have a "concrete idea" of details by around May.
El Prat is a base for low-cost carrier Vueling whose chief, Alex Cruz, detailed in an internal letter to staff, earlier this year, his initial expectations on Ryanair plans from Barcelona.
He believed the airline was gearing up to station at least five Boeing 737-800s at El Prat, with operations to Brussels Charleroi, Milan Bergamo, Santander, Ibiza and Las Palmas.
A source within Spanish airports authority AENA says that Ryanair "has booked slots" but is unable to provide any further details.
The Ryanair spokesman says that negotiations are still continuing and the number of aircraft and destinations has not yet been agreed.
He states that the airline's plans to serve El Prat will not necessarily have consequences for Girona and Reus, pointing out that it serves multiple airports in London and adding: "Not everyone who comes to Barcelona wants to go to the city centre."