Turkey will go ahead with its plan to build a $5 billion highway, including a bridge across the Bosphorus Strait linking Europe and Asia, even if it fails to attract any bids for the tender, the country's transport minister said.

Four companies, out of an initial 18 interested parties, have told Reuters that they pulled out of the process and at least one company source predicts the tender will receive no bids at all.

"Postponing the tender is out of the question, we will put our second plan into action if we receive no bids," Turkish transport minister Binali Yildirim told reporters without disclosing any details of the plan.

A spokesman for the ministry added that the minister wasn't prepared to share any details publicly at this stage.

Company sources told Reuters that Italian company Astaldi , Turkish firm STFA, Varyap and Cengiz Insaat, companies which acquired formal tender specifications, will not bid in the Turkish North Marmara Highway project tender due to financing difficulties.

"We do not expect the other companies to bid either," a senior company official at one of the four companies added.

Some 18 companies out of an initially interested 33 acquired formal tender specifications to submit offers for the North Marmara Highway project, including Japanese, Russian, Spanish, Austrian and Italian firms, as well as Turkish companies.

The General Directorate of Highways tender had been postponed until January 10 at the request of the interested companies.

The winning company will have operation rights for 25 years.

Obayashi, Mitsubishi, Itochu and IHI from Japan, Astaldi of Italy, Moskovskiy Metrostroy and NPO Mostovik of Russia, Stradag of Austria, FCC Construction of Spain and Turkey's Mapa, Cengiz, Park, Varyap, Yuksel, Kolin, Nurol, STFA and Gulsan are companies who acquired the official documents.

The North Marmara Highway Project consists of a 414 km (260 mile) highway connecting Adapazari on the Asian side of the Marmara region to the Tekirdag region on the European side.

A third bridge over the Istanbul Strait, complete with a railway track, is also part of the project, which will be Turkey's second largest built-operate-transfer model project.

Two bridges over the Bosphorus generated 216 million lira ($116 million) income, while income from Turkey's highways reached 516 million lira in 2011, General Directorate of Highways figures showed. (Reuters)