La Liga clubs earned more from player sales in the close season than any league in history, including a record amount from selling talent to rivals abroad, according to a study published on Thursday.
The figures compiled by Barcelona-based Prime Time Sport underlined how Spanish top-flight teams, excluding wealthy Real Madrid and Barcelona, are increasingly being forced to cash in on top performers to stay afloat.
They also suggested UEFA's Financial Fair Play rules, currently being phased in and designed to prevent clubs spending more than they earn, are beginning to bite.
La Liga clubs sold players worth €480m ($630m) in the transfer window which closed on Monday, Prime Time's latest Football Transfer Review showed.
Almost a third of income, or €139m, came from deals with clubs outside Spain.
The majority of players were sold to English Premier League sides, including Mesut Ozil leaving Real Madrid for Arsenal, Alvaro Negredo and Jesus Navas joining Manchester City from Sevilla and Roberto Soldado switching to Tottenham Hotspur from Valencia.
La Liga clubs spent €400m buying players, the second highest amount ever, yielding a net profit of around €80m, with Real (€183m) and Barca (€57m) accounting for 62 percent of the outlay.
Outside the big two, the world's richest clubs by income, four clubs did not spend anything at all on players and nine laid out less than €3m each.
"La Liga is now more of a seller than a buyer and except for Real and Barca is experiencing difficulties in holding on to talent," Prime Time said.
"As many as 13 of the 20 teams in La Liga took their chance to cash in and clean up their accounts."
The study also showed that after Real's purchase of Gareth Bale from Spurs for a record €100m the club has spent €611m on players in the past five years, almost 40 percent of the total for La Liga.
They have spent 75 percent more than arch-rivals Barca (€348m), who bought only one player in the close season – Brazil forward Neymar from Santos for €57m – for the first time in a quarter of a century.
