The bid from the Catalan club, claims Graille, is "completely" superior to the offer from United, and the PSG president added that he is keen to get the sale done as soon as possible.

Even though Barcelona have proposed the inclusion of two players as part of their bid - which is believed to be around £21m - PSG are warning that United must move swiftly to increase their £

15.5m bid, and do so significantly, in order to remain in the race for the Brazilian.

Asked whether the offer from Old Trafford was insufficient compared to the sum which Barca are prepared to pay, Graille said: "Yes, completely. However nothing has been done yet."

Graille wants the situation resolved "as soon as possible", and the longer Barcelona's bid remains the preferred option for PSG, the more likely they are to sign the striker.

When asked whether there were meetings planned with United chief executive Peter Kenyon, Graille added: "Nothing has been planned so far but things can happen very quickly."

Barcelona have made Ronaldinho their prime target since losing out on David Beckham to Real Madrid, and their new president Joan Laporta is eager to secure a big-name signing - both to improve a team which last season descended into mediocrity, and to increase the club's worldwide profile.

Laporta stated Wednesday he has no intention of getting into a bidding war with United for Ronaldinho.

"Barcelona tabled a significant offer to Paris Saint-Germain and at the last moment, when we were on the point of signing contracts, Manchester United came in with a counter bid and sparked off a bidding war," said Laporta.

"We don't think it's in Barcelona's interests to up our bid to Manchester's level, which, it seems, is very high," he added.

"Barcelona made a sizeable offer and will stick to it," said the Catalan club's boss, and that "the matter is now closed."

According to Laporta, Barcelona's sporting vice-president Sandro Rosell went to Paris on Tuesday to reach an agreement with Ronaldinho and his agent and brother Roberto Assis.

The latter, talking to AFP by telephone Wednesday afternoon, declined to comment on the state of play in the negotiations. According to him, Ronaldinho is still in Brazil.

Ronaldinho has said that he wants to join United but he and brother Roberto Assis, who acts as the 23-year-old's agent, are understood to be disappointed by the protracted nature of the transfer.

He is also known to be enthusiastic about playing in Spain, but would have preferred to join Madrid rather than Barca, only for the team from the Spanish champions to withdraw their interest when Ronaldinho dismissed their suggestion that he should stay at PSG next season on a loan basis.

PSG have stopped Ronaldinho's wages and he remains in Brazil - seven days after he was due to report back for pre-season training.

Ronaldinho is best known for his 40 metre free kick which fooled England goalkeeper David Seaman in the World Cup quarter-finals.