RIO DE JANEIRO - Brazilian state oil company Petrobras said Monday it suspended test production at a well in the offshore Tupi field due to an equipment problem.

The massive Tupi field forms part of a cluster of offshore oil fields buried beneath a layer of salt far below the ocean's surface that hold the potential of turning Brazil into a major energy exporter.

Petrobras said it found a manufacturing problem with fixation bolts used in a device called a Wet Christmas Tree at well 3-RJS-646, part of an Extended Well Test (EWT) at Tupi.

The well was closed for the operation to be carried out, and the EWT will be continued after the replacement has been completed, the company said in a statement.

Petrobras did not specify which company manufactured the equipment or when the well test would resume, but said it did not detect any oil leakage.

It added the incident would not affect the development of the Campos Basin sub-salt projects. (Reporting by Brian Ellsworth; Editing by John Picinich)