LONDON, Sept 21 (Reuters) - Blockchain-based fantasy soccer game Sorare has raised $680 million in a funding round led by SoftBank (9984.T), with players including ex-England international Rio Ferdinand and Spain"s Gerard Pique also investing, the company said on Tuesday. Paris-based Sorare said the investment valued the company at $4.3 billion. Founded in 2018, Sorare is an online game where players buy officially licensed cards representing soccer players and build teams which play against each other, with the outcome based on the players" performance in real-life games. The cards are traded in the form of non-fungible tokens (NFTs), a kind of crypto asset which records the ownership status of digital goods on the blockchain. read more The market for NFTs has seen explosive growth in 2021, with collectible and sports-related the most popular types of token. read more "We think NFTs represent a new paradigm in the collectability, usability, and engagement with assets," Michel Combes, president of SoftBank Group International, said in emailed comments. "This evolution from physical assets to digital assets is very powerful, and creates a lot of exciting potential business models." Sorare is the largest sports-based NFT platform by sales volume, according to NonFungible.com, a website which tracks NFT market data. It plans to open an office in the United States and expand into sports other than soccer. "We saw the immense potential that blockchain and NFTs brought to unlock a new way for football clubs, footballers, and their fans to experience a deeper connection with each other," said Nicolas Julia, CEO and co-founder of Sorare. "We believe this is a huge opportunity to create the next sports entertainment giant." Since January 2021, there have been $150 million of sales on Sorare, which accepts payments via credit card and the cryptocurrency ether. The most expensive unique card is of Cristiano Ronaldo, which was bought for 245,072 euros ($287,420.44) on March 13. The fundraising round was SoftBank"s first time investing in Sorare, via its SoftBank Vision Fund 2. SoftBank"s Latin America fund also contributed, which Combes said was because SoftBank can use its relationships with U.S. and Latin American soccer leagues and its investment in broadcaster Televisa-Univision, to increase Sorare"s user base there. This is not SoftBank"s first foray into NFTs: it also led investment in the NFT marketplace OpenSea in July and invested in the decentralised finance platform Juggernaut in March. Other investors in Sorare"s raise include: venture capital firms Accel and Bessemer Ventures as well as the footballers Pique, Ferdinand, France"s Antoine Griezmann and Spain"s Cesar Azpilicueta. ($1 = 0.8527 euros)