The State Ports Authority picked an urban design firm on Tuesday to update its master plan for some of the most valuable and underdeveloped waterfront property on the Charleston peninsula.

The SPA must now finish negotiating the terms of the contract with New York-based Cooper Robertson and Partners, a group that previously had worked on the Charleston Visitor Center, the Judicial Center and the College of Charleston's School of Education.

The cost of the updated plan cannot exceed $700,000.

Cooper Robertson will spend four months working on a plan to improve the SPA's cruise-ship terminal near the end of Market Street and the nine acres of waterfront property around it.

The selection was made after the maritime agency collaborated with city of Charleston officials.

Joe Bryant, the SPA's vice president of terminal development, said Mayor Joe Riley spent a half-day working with the authority to decide between two finalist firms. Bryant said the choice "came down to scope," that Cooper Robertson brings real estate and development expertise.

Plus, according to Bryant, the firm focused on public involvement and project financing.

"If this project is going to work, it's got to be something the city is agreeable with and the community is agreeable with," Bryant said.

The SPA developed an ambitious master plan 13 years ago to revamp its then-outdated cruise terminal and to transform the prime waterfront acreage surrounding it into a thriving commercial hub that showed shops, lodgings and dining establishments. Little has changed since then.

In addition to revisiting the 1996 plan, Cooper Robertson also must include improvements laid out in the post-Sept. 11 Maritime Transportation Security Act and work around federal flood-zone requirements.

Once the firm completes the plan, the SPA will seek development partners to help implement it.

Reach Allyson Bird at 937-5594 or abird@postand