Likewise, Quijano hailed the accord as one which "protects the interests of the Panama Canal within the terms of the contract, and [respects] our mutual positions."
GUPC had been in dispute with the canal authority in part over geological difficulties which obliged the builders to spend much more on cement than expected.
GUPC said it based its estimates on incorrect data provided by the Canal Authority.
The 50-mile-long canal, completed by U.S. interests in 1914 to offer a shorter, safer route between the Atlantic and Pacific, is used by 13,000 to 14,000 ships each year.
In 1999, ownership of the canal reverted from the United States to Panama.
The project to add a third set of locks to the canal had originally been due to be completed next year.
But the project was running nine months late at the end of 2013, and has slowed further this year.
Copyright Agence France-Presse, 2014