It is understood emergency flaring at Mossmorran will stop later today, after six days.
Bosses at the Fife Ethylene Plant say work to commisson a new pump has 'progressed well', and normal operations should now resume.
The most recent bout of flaring, which started on Saturday, has led to renewed calls for an investigation into its health implications for local people.
Scotland's Public Health Minister Aileen Campbell is now urging the environmental watchdog SEPA to include noise and light pollution in its monitoring of the site.
Sonia Bingham, ExxonMobil Chemical Limited FEP plant manager, said:
“My dedicated team at FEP continues to focus on returning this pump to service as quickly and diligently as possible.
"We are working tirelessly with our pump suppliers to achieve this, while doing everything we can to minimise the size of the flare and any disturbance to the local community.
"While nobody wants flaring, it is necessary when a production issue occurs and is permitted by SEPA subject to strict regulation.
"We continue to work closely with SEPA as we resolve the issue.
"We apologise to local communities for any disturbance and remain in contact with local agencies and community groups to ensure local residents are kept informed."
A Scottish Government spokesperson said:
“We understand the concerns of local residents and the Minister will write to SEPA to ask how they were assessing and addressing potential public health impacts from flaring activity at Mossmorran.
“The Scottish Government is aware that SEPA is continuing to work with ExxonMobil Chemical Ltd and Shell UK Limited to understand the circumstances around the flaring at Mossmorran.
"We understand that both companies have responded positively to engagement with SEPA.”