The new port will help Colombo retain and enhance its position as a transhipment hub for the south Asian region, officials said.
"We extended the deadlines because there were a few requests made by bidders," a senior SLPA official said.
The last date for issuing bid documents has been extended to May 15 while the closing date for submitting proposals to build and operate the terminal has been extended to June 16, SLPA officials said.
The last date for bidders to seek clarifications is May 18.
Fourteen potential investors, including shipping lines and port operators, had collected bid documents by the original date for collecting documents on April 10.
The parties who have collected bid documents so far include Maersk, the world's biggest shipping line, APL, another global shipping line, Hutchison Port Holdings, a big global port terminal operator based in Hong Kong, and China Merchant Shipping, another Chinese Hong Kong terminal operator.
Others are Gulftainer, a port operator b