MEXICO CITY, Oct 15 (Reuters) - An oil platform explosion that claimed seven lives and caused crude output from four nearby fields to plunge nearly 70 percent will not lead to any fine against state-run oil company Pemex, the head of Mexico's new oil safety agency said on Thursday.
The April 1 blast at the offshore Abkatun A Permanente processing platform operated by Pemex in shallow waters at the southern edge of the Gulf of Mexico also left 45 injured.
The probe into the accident is the first by the oil safety agency known as ASEA, which was created under an energy reform completed last year.
ASEA's regulations will apply to both Pemex and new private producers, which the reform opened the door to in a bid to reverse years of flagging crude output.
"We have a basic focus on prevention, and we have to help Mexico's oil and gas sector be the cleanest and safest on the planet," ASEA director Carlos de Regules said in an interview.
After the explosion, production at the Abkatun, Ixtal, Chuc and Caan fields that feed the platform fell by a combined 67 percent to about 43,500 barrels per day (bpd) at the end of April, from about 132,400 bpd a year earlier.
There will be no sanctions because the probe revealed no failure to comply with applicable regulations, de Regules said.
The explosion was caused by a leak in a rarely used gas fuel line which "showed an unusual kind of accelerated corrosion due to the presence of micro-organisms and sulfuric acid within the gas," he added.
The two elements caused a rupture in the line and the escaping gas ignited, he said, adding that measures are being put in place to prevent a repeat of the accident, including a revision of dozens of miles (km) of similar gas lines.
De Regules could not say how much compliance with the measures will cost.
The Abkatun platform accident, one of at least four reported by Pemex this year, significantly contributed to a nearly 9 percent fall in overall crude output during the first half of this year, Pemex said in a regulatory filing last month.
Pemex said on the day of the accident the impact on output would be "minimal."
Crude production from the four fields that supply the Abkatun platform was about 103,400 bpd in August, down 13 percent compared to the same month last year.
Reporting by David Alire Garcia and Adriana Barrera; Editing by Tom Brown