"The level of engagement and the scale of the bids reflect the marketplace's belief in our proposed model and the enormous, untapped potential for European basketball," Tatum said in a statement.
"We will now review the bids in more detail and shortlist the partners who share our vision and commitment to accelerating the growth of the game across the continent."
NBA governors again expressed overwhelming support for the proposed league at the Board of Governors meeting on March 24-25, sources told Reuters. More than 120 prospective investors, including existing teams, outside investment groups and high-net-worth individuals, have shown serious interest in the venture.
The NBA has received multiple bids in the $500 million to $1 billion range, including several above $1 billion, the sources said.
There is competition from a range of investors across each of the league's 12 target cities. Those cities include London, Manchester, Paris, Lyon, Rome, Milan, Barcelona, Madrid, Berlin, Munich, Athens and Istanbul.
In recent weeks, the NBA has held talks with more than a dozen existing basketball teams and received bids from multiple clubs, including current EuroLeague teams, sources said.
The NBA and FIBA plan to take a phased approach, prioritising the most serious bids that align with their long-term vision, the sources said. The NBA would then engage with its Board of Governors to select partners, while FIBA would follow its own process.
Announcements on final terms, the league's launch and participating teams are expected to come on a rolling basis rather than all at once.
The NBA and FIBA also remain in active talks with the EuroLeague, but a successful bid through their process is the only way to secure a permanent place in the new competition, the sources said.