According to the rating agency, Petroperú's operational and financial condition has weakened as a result of unexpected problems and the subsequent stoppage at one of Talara's units.

S&P lowered Petroperú's credit rating to 'B' from 'B+', while at the same time putting the oil company's solvency rating in negative watch.

The latter implies that S&P could reduce the rating to 'B-' or less in the next three months.

This is in line with Petroperu's need to obtain a waiver consent to avoid a technical non-compliance due to its delay in obtaining audited statements.

According to the rating agency, Petroperú's operational and financial condition has weakened as a result of unexpected problems and the subsequent stoppage at one of Talara's units.

Recent events have raised questions about the government's suppport to Petroperú, although at this stage there are hopes that the administration will intervene to prevent a default.