The State Ports Authority has signed another long-term contract that will increase container business at the Port of Charleston.

The maritime agency said it inked a four-year agreement with the New World Alliance, a consortium of major carriers that includes American President Lines, Hyundai Merchant Marine Co. and Mitsui OSK Lines.

The SPA said the deal secures its existing business with NWA and adds about 52 vessel calls a year, increasing the group's container business with Charleston by 50 percent.

NWA currently makes 104 ship calls a year in Charleston.

The new service will link Charleston with Southeast Asia and the Indian subcontinent via the Suez Canal.

"It's what people here have been waiting for: a new Suez service," said Byron Miller, SPA spokesman.

Called the Suez Express, or SZX, the service will rotate eight vessels, each capable of carrying the equivalent of between 4,000 and 4,500 20-foot-long shipping containers.

The Suez service begins in July and will include calls in Colombo, Sri Lanka; Jebel Ali, United Arab Emirates; Kelang, Malaysia; and Singapore. While in Charleston, the ships will be serviced at the Wando Welch Terminal in Mount Pleasant.

NWA's existing service, the Atlantic Pacific Express, or APX, has two weekly calls in Charleston and connects the port with Asia and northern Europe, bringing more than 175,000 TEUs annually.

The Port of Charleston handles nearly 2 million 20-foot containers a year.

George Hearn, vice president of APL's southern region, said the alliance weighed several factors in its decision to increase business in Charleston, including the port's productivity level, its proximity to the ocean and its deep shipping channel.

"Overall, APL ships can get in and out very quickly," Hearn said. "Time is money to a ship operator."

The new contract enhances service to two critical cargo hubs for port users, said Fred Stribling, SPA vice president of marketing and sales. Singapore is considered a vital trans-shipment hub for Indonesia and all of Southeast Asia, and Colombo draws cargo from the Indian subcontinent, he said.

Tuesday's agreement is the SPA's second commitment from a major steamship line in the last five days.

Last week, Mediterranean Shipping Co., the world's second-largest container carrier and the port's No. 2 customer, signed a five-year agreement with the SPA that will bring more than 230 ship calls annually to the port.

That agreement was effective May 1.