CHARLESTON, S.C. - The 21 companies interested in offering ideas on how the state should expand port operations in Charleston and build a new port in the Lowcountry have five weeks to make proposals.

On Thursday, the State Ports Authority held the last of three information session for the 15 steamship lines and six terminal operators interested in those projects.

By Aug. 1, they are supposed to offer ideas on how best to pursue a three-berth container terminal on a 280-acre site at the former Navy Base in Charleston and an 1,800-acre site in Jasper County that would serve shipping lines on the Savannah River.

The Ports Authority will use the best ideas on financing and operating the facilities. Plans now call for the state to seek formal proposals on the projects this fall.