Brazilian operators will face new limitations on chartering-in tonnage to the country's cabotage market if proposed regulations are enacted, even when domestic-flag ships are unavailable, law firm Kincaid Mendes Vianna Advogados says.

Oil giant Petrobras, a charterer of both tanker and offshore vessel tonnage, would be among those most affected by the proposed rules.

The country's National Agency of Waterborne Transport (Antaq) has rules that have been couched as an attempt to unify chartering rules and boost investment in the cabotage shipping trades.

But lawyers Godofredo Mendes Vianna and Juliana Furtado, both of Brazil's Kincaid Mendes Vianna, say that one of the most controversial changes would restrict the number of foreign-flag ships that Brazilian operators can charter in.

Antaq's proposal would allow them to charter no more than double the number of foreign-flag ships than they have in their Brazilian-flag fleet.

Current rules place no such limit, as long as there are no Brazilian-flag ships available to meet the operator's needs.

"If it is approved, the new resolution could considerably affect the capacity of certain companies to continue to use foreign-flag ships in Brazilian waters," the lawyers write in a note to clients.

Petrobras is among those most affected because it has such a small fleet of domestic-flag offshore vessels compared to some 250 units chartered in from the international market, the lawyers say.

Antaq will continue to take public comments on the proposed rules until 5 November 2015

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