The Six Nations committee have received a letter from the Argentina Rugby Union requesting a place in an expanded tournament.

The Pumas are anxious to build on their third-place finish at the World Cup by gaining entry into one of the established annual competitions.

The Tri-Nations is another possibility but, with almost the entire national squad playing their rugby in Europe, the Six Nations remains Argentina's preferred option.

A Six Nations spokesperson said: "The Six Nations have received a letter from the Argentinian Union. We will acknowledge receipt of that letter to the Argentinians."

The International Rugby Board are determined to find a home for Argentina, who beat France twice, Ireland and Scotland en route to their best ever World Cup finish.

But there are commercial and logistical complications that would have to be considered, such as existing television and sponsorship deals.

And an extra week would also have to be found in an already-packed season to incorporate a seventh team into the tournament.

Hugo Porta, the former Pumas outhalf and advisor to the Union Argentina de Rugby, will present the Pumas' case for inclusion to the International Rugby Board later this month.

Porta said: "We will present our strategic plan to the IRB, which we have been working on at the UAR for a long time with the purpose of getting Argentina included in future international competitions.

"So many of the current players consider it more viable to play in the Six Nations in Europe because it's there that most of the Argentinian players play."

The IRB are meeting in London for a forum to discuss ways of implementing an integrated global season.

If they can thrash out a solution to the thorny issue, it would make Argentina's move to the Tri-Nations more feasible on a logistic front, given the players would not miss any European club rugby.

Pumas centre Felipe Contepomi believes the long-term future lies in the Tri-Nations, otherwise they risk being too reliant on European clubs to keep signing up Argentinian talent.

"If it is in the northern hemisphere, it could be good for the short term, for this team of the Pumas, but you will be depending on many European teams contracting Argentine players," he said recently.

"If, in 20 years' time, that doesn't happen then you will have a very big problem. You have to make the way of growing Argentinian rugby.

"I think if we go to the southern hemisphere, we have to be based in the southern hemisphere. We have to have a professional tournament at home and develop a professional structure."

But Argentina appear set on joining an expanded Seven Nations.

"In my view, it's better for Argentina to be in the Six Nations," said Marcelo Loffreda, who took over at Leicester yesterday after eight successful years as Pumas coach.

"All the overseas players are playing in the northern hemisphere so it's impossible to make a competitive team in the Tri-Nations.

"It's not going to be possible for Argentina to have a professional league. We don't have the sponsors or the money.

"The only way Argentina can stay this competitive is to get the best players having professional preparation and they have to go overseas for that."