Replying to an RTI query, the ministry said it was exempted from providing information related to commercial confidence and trade secrets.
"The information sought in your application falls under the exemptions provided under Section 8 (1) (d) of the Right to Information Act," it said.
The section bars information including commercial confidence, trade secrets or intellectual property, the disclosure of which would harm the competitive position of a third party.
The Shipping Ministry was asked to give details of companies of foreign origins which had bid for any port projects (expansion, renovation, technological upgrading, etc), and denied security clearance in the past five years.
The Section 8 (1) (a) exempts information, disclosure of which would prejudicially affect the sovereignty and integrity of India, the security, strategic, scientific or economic interests of the State and its relation with foreign State.
The other clause bars disclosure of information which would endanger the life or physical safety of any person or identify the source of information or assistance given in confidence for law enforcement or security purposes.