Houston Rockets ownership is in substantive talks with the Connecticut Sun over the potential purchase and relocation of the WNBA franchise, sources told ESPN this week.

The discussions have been described as “positive,” and Rockets ownership has improved its offer to a number the Sun might find acceptable, a source close to the situation said.

The source said that while a formal offer has been discussed, the parties have not signed an exclusivity agreement and there has not been a decision on the future of the franchise.

The WNBA previously indicated strong interest in a return to Houston. At the league’s three-team expansion announcement in June, commissioner Cathy Engelbert specifically highlighted Houston and Rockets owner Tilman Fertitta as “up next” and “the one we have our eye on.”

The Sun have been owned by the Mohegan tribe since 2003, when they bought and relocated the franchise from Orlando, Florida, to Uncasville, Connecticut. A sale to Rockets ownership would mark the latest example of the WNBA moving toward having more teams with NBA owners.

The Sun launched a process to explore investment options over a year ago, initially seeking to assess opportunities for a limited partnership sale that would help fund an infrastructure build.

Earlier this year, Houston was among the groups that expressed interest in buying the Sun outright, eventually raising its offer to $250 million, the amount that Cleveland, Detroit and Philadelphia paid in an expansion fee earlier this year.

In early July, Sun ownership reached a deal to sell the team for a record $325 million to a group led by former Celtics minority owner Steve Pagliuca that would have moved the franchise to Boston. The WNBA effectively blocked the deal from progressing any further, holding firm that “relocation decisions are made by the WNBA Board of Governors and not by individual teams” and that cities that have already gone through the expansion process have priority over Boston.

The WNBA then offered to buy the Sun for $250 million, which would have allowed it to facilitate a sale to a market of its choice. There was a belief at the time that the league was looking to move the Sun to Houston after Houston did not get an expansion team in June.

Sun ownership has more recently explored a potential opportunity where funds affiliated with the state of Connecticut could be used to buy a minority stake in the franchise. But those talks have slowed, sources told ESPN.

The hope is that a resolution on the franchise’s future can be determined before free agency, where all but two league veterans are not under contract. The exact timing of free agency, though, is uncertain as the league and players’ union continue to negotiate a new collective bargaining agreement, with a deadline for a deal currently set for Jan. 9.

The Houston Comets were an iconic original franchise that won the league’s first four championships (1997-2000) and was home to some of women’s basketball’s biggest stars in Sheryl Swoopes, Cynthia Cooper and Tina Thompson before the franchise disbanded after the 2008 season.