Double taxation - in which a company or individual pays tax to two jurisdictions - can discourage trade because of the extra costs involved.
Japanese businesses were early investors as India opened its state-controlled economy, with Suzuki Motor now holding a majority stake in India's top automaker Maruti, but India's economic ties have grown more rapidly with other countries.
India's imports from Japan fell from 2.47 billion dollars in 1998-1999 to 2.15 billion dollars in 2001-2002, the last year figures were available from the Indian commerce ministry. Exports followed a similar pattern.
Japan revised a tax treaty with the United States last March and is in talks on treaty revisions with Britain, the Netherlands and the Philippines.