SEATTLE, WA - The city has opened up a formal request for ideas about how to reform Seattle Center's KeyArena into a venue that can support an NHL or NBA team - and that includes ideas that call for the arena's demolition.

The city opened an RFP (request for proposals) process Wednesday for KeyArena. Bidders can submit ideas to create a "world-class civic arena" that would be able to host a pro sports team, plus concerts and other entertainment events.

"We have a unique opportunity to re-imagine KeyArena and continue the growth and redevelopment of Seattle Center," Mayor Ed Murray said in a statement released Wednesday. "There is significant interest in working with the City of Seattle to create a civic arena that fulfills the current and future needs of our growing city that serves the greatest number of community members. I, along with others at the City, are looking forward to reviewing proposals with the community. We are 100 percent committed to finding the best deal for Seattleites."

Ideas for redevelopment have to adhere to certain city guidelines. You can find the full RFP on the city's website here.

The RFP comes as the city is still involved in a legal agreement with billionaire Chris Hansen to potentially build an arena in Sodo that would be a home to a pro basketball and hockey team. That agreement expires on Dec. 3, 2017. Hansen has been trying for years to lure an NBA team back to Seattle; in October he offered to build an arena entirely with private money.

KeyArena first opened in 1962, and was formerly the home of the Seattle SuperSonics. In current form, the arena can hold about 17,000 fans for basketball games; the Portland Trail Blazers' Moda Center can hold about 20,000, by comparison.

Image via Flickr user Isa Sorensen