Bidding competition for the contract to build eBay's next data center in Phoenix, Arizona, is coming to a close. This week, the company announced a list of six finalists, from which it will choose the winner. Next week, each of the companies on the list will have two hours to sell their solution to the online retailer's review board. 

Dean Nelson, senior director of eBay's global data center strategy, architecture and operations, posted the list on his blog on Data Center Pulse. 

"The intent was to encourage companies to participate in the RFP, level the playing field and spark some real innovation," Nelson wrote about the request for proposals eBay circulated in August. "In the past we created a list of vendors that we believed were qualified to design and deliver a data center for us. We also told them how we want to build it. But this time, we just gave the parameters that we wanted to achieve." 

The company has required the following characteristics for its future data center: multi-tier, modular, vendor-agnostic, scalable, delivery of multi-temperature air and liquid to each location, rack-to-container mixtures, 100 percent free cooling in Arizona year round, future-proof, extreme density and more. 

eBay approved requests to participate in the RFP process from 37 companies and turned away another 15 because they had missed the deadline for proposal submissions. 

Here are the finalists in alphabetical order: 

1. Primary: DPR. Partners: Liebert, Aecom, ESD

2. Primary: EDI. Partners: Winter Street Architects, AHA Engineers, Active Power

3. Primary: Kling Stubbins

4. Primary: McKinstry

5. Primary: RTKL

6. Primary: Skanska. Partner: Cosentini

Other contestants included Dell, Gensler, HP, BKM, Bruns-Pak and others.