By Giulio Piovaccari and Elvira Pollina

MILAN (Reuters) - Cryptocurrency firm Tether is open to all future options with regards to increasing its investment in Juventus, the Italian Serie A soccer club where it has built a 5% stake, and has the financial capacity to do so, its CEO Paolo Ardoino said on Tuesday.

Tether, the world's fourth largest cryptocurrency, on Friday announced it held a minority stake in Italy's most popular soccer club, which is controlled by the Agnelli family through their investment company Exor and is also listed on the stock exchange in Milan.

Asked whether Tether was interested in increasing its stake and potentially buying the club, Ardoino said "you can buy only what someone wants to sell".

"We're fine to remain as minority investors as well as engaging in different talks," he told Reuters in an interview.

Ardoino, an Italian national and Juventus supporter, said Tether notified Italian market regulator Consob it had crossed the regulatory threshold of 5% of Juventus voting rights.

He said Tether has built its stake over the past two months through share purchases on the open market.

"We don't want to be hostile, we don't want to be seen as aggressive, we just want to help (Juventus) because we see a huge and unexpressed potential," he said.

"Our main goal is to cooperate with the (Juventus) managers and owner."

With a market capitalisation currently around one billion euros ($1.04 billion), a 5% stake in Turin-based Juventus is worth around 50 million euros. Tether, which does not release audited financial reports, said in January its 2024 net profits exceeded $13 billion.

Ardoino said that on the back of that profit, "we have got a lot of opportunities."

Exor holds a 64% stake in Juventus. It has always denied any plans to sell the club.

Ardoino said he was willing to meet with Juventus owners to discuss potential development of relations with the club. Cooperation could include exploiting the firm's payment platform and 400 million-strong user base globally, especially in emerging countries, to help Juventus enhance its brand.

"Soccer clubs need to take a more forward-looking approach to how to use these new technologies ... to communicate and interact with their fan base, in a new way," he said.

Tether has emerged as a dominant force in the booming market for stablecoins, designed to maintain a constant value by being pegged to traditional currencies and offer users a way to move money between cryptocurrencies without exposure to price swings.

Juventus, which has been controlled by the Agnelli family for a century, has raised around 900 million euros in fresh capital from its shareholders over the past six years.

It reported a loss of nearly 200 million euros in the financial year ended on June 30, 2024.

There are more than $140 billion Tether tokens in circulation acting as a proxy for the U.S. dollar, Tether says on its website. Tether says these tokens are fully backed by Tether's reserves.

Regulators have long-standing concerns that growing stablecoin reserves expose the broader financial system to bigger risks, because they act as a bridge between the crypto universe and mainstream financial markets.

U.S. regulators also have warned banks that stablecoin reserves could be subject to rapid outflows, for example if holders rushed to exchange such tokens back into traditional currency.

($1 = 0.9570 euros)

(Reporting by Elvira Pollina and Giulio Piovaccari, additional reporting by Elizabeth Howcroft in Paris; Editing by Keith Weir)