An agreement announced in March between the Panama Canal Authority and the new locks contractor set completion for December 2015.
According to the Associated Press, Panama Canal administrator Jorge Quijano told a South Carolina trade conference on Tuesday the completion is set back to 2016 but did not specify a date.
Meanwhile, a separate AP report from Madrid cited Panama President Juan Carlos Varela as saying the project is expected to be completed in late 2015 and open to ships in early 2016.
Spain's Sacyr Vallehermoso leads the consortium that forms the new locks contractor. Other members are Italy's Impregilo, Belgium's Jan de Nul Group and Panama's Constructora Urbana.
On Monday the third shipment of four gates for the new locks arrived at the Atlantic entrance of the waterway.
The gates were delivered Sunday aboard the post-Panamax vessel Xia Zhi Yuan 6, owned by COSCO Ocean Shipping. The shipment began its journey from Trieste, Italy, on Aug. 17. One more shipment, due in January 2015, is left before all 16 gates required for the third set of locks are on site, according to the Panama Canal Authority.
The expansion is 79% complete.