(Adds details of Cade ruling, context)
By Bruno Federowski
BRASILIA, May 9 (Reuters) - Brazil's antitrust regulator on Wednesday approved the sale of a Vale SA fertilizer unit to Yara International ASA in a deal that will allow the Norwegian group to produce nitrogen-based fertilizers in Brazil.
Six of regulator Cade's seven board members voted to approve the $255 million transaction without demanding any asset sales or restrictions. One board member, Paula Farani, abstained from voting.
A Cade technical body approved the transaction in March, arguing it would not grant Yara a dominant foothold in any of the markets where it operates.
Yet Cade board member João Paulo Resende last month asked the regulator's board take a closer look at the deal after state-controlled oil company Petróleo Brasileiro SA, known as Petrobras, announced it would mothball two fertilizer plants in northeast Brazil.
Maurício Maia, the rapporteur in charge of the transaction at Cade, said it remained unclear whether Petrobras would indeed halt operations at the two fertilizer plants and is studying how to maintain its presence in local ammonia markets.
High transportation costs would prevent Vale's fertilizer unit from providing ammonia to clients in the northeastern region, he added. (Reporting by Bruno Federowski Editing by Jeffrey Benkoe)