Hedge-fund manager Chris Hansen is no longer alone in is quest to bild a state-of-the-art sporting arena in downtown seattle as Microsoft CEO Steve Ballmer as now thrown his hat in the ring as part of the investment grouplooking to return the NBA and NHL to Seattle.

Ballmer will be part of the investment group for both the building and ownership of the arena as well as the acquisition of an NBA franchise, first announced on the Mitch in the Morning radio show on SportsRadioKJR and according to a letter that Hansen sent to King County Executive Dow Constantineand and Seattle Mayor Mike McGinn on Wednesday. Ballmer is a longtime Sonics supporter and was part of a last ditch effort to try and keep them in Seattle. Meanwhile, he and a few other investors proposed renovations to KeyArena.

Also part of the investment group will be Erik and Peter Nordstrom, who's family owned the Seattle Seahawks from 1976-1988. The Nordstrom duo will also invest in both the arena and a franchise.

The project will need about $290 million in private funds and around $200 million more from the city and county through 30-year bonds. Any franchise that comes to Seattle and uses the arena would be required to sign a non-relocation agreement that would last for the life of those bonds.