DALLAS (Standard & Poor's) - Standard & Poor's Ratings Services has assigned its 'A+' rating to the South Carolina State Ports Authority's (SCSPA) series 2015 port revenue bonds. At the same time, Standard & Poor's affirmed its 'A+' rating on the port's 2010 bonds. The outlook is stable. "The rating reflects our assessment of the credit profile of the Port of Charleston, an operating container port that has historically maintained what we consider strong operating margins," said Standard & Poor's credit analyst Anita Pancholy. "We expect these to stay strong at albeit lower levels as the port implements its large, demand-driven capital program," Ms. Pancholy added. Bond proceeds willfinance improvements to the port's existing facilities and complete the remaining site development of the port's new Navy Base Terminal. The SCSPA operates two ports: the smaller Port of Georgetown (a 45-acre facility approximately 60 miles northeast of Charleston that is limited by harbor depth); and the larger Port of Charleston, where the overwhelming share of revenue-producing activity occurs. The Charleston facility can accommodate nearly all cargo types. It has six terminals, with 1.5 million square feet of warehouse and transit shed space and more than 500 acres of container storage space for import and export, break-bulk cargo, roll-on and roll-off (for instance, cars and trucks), as well as containerized cargo. The stable outlook reflects S&P's expectations that DSC and liquidity levels will remain strong during the two-year outlook period. The outlook also reflects S&P's expectation that port volume will remain stable and supporting credit quality. S&P doesn't expect to raise the ratings during the two-year outlook period, given the likelihood that financial margins will decline beyond the outlook horizon as the port further leverages. S&P could lower the rating if the port's capital costs outpace growth in volume and revenues to support additional leverage. They could also lower the rating if financial margins or liquidity levels are materially lower than their expectations.