The Turkish government has said work will begin next year on a new canal in Istanbul to cut Bosporus shipping traffic.
Turkish media cited transport and infrastructure minister Mehmet Cahit Turhan as saying the project will take five years.
The waterway will have a service life of at least 100 years.
A total of 10 new bridges and a new port will also be constructed.
The 43km canal will be 25 metres deep and 400 metres wide.