Greece's biggest refiner Hellenic Petroleum said late on Wednesday it was planning to temporarily halt production at a flexicoker unit in its Elefsina refinery to repair a technical glitch.
"The company has...prepared all required actions to set up a shutdown of the unit," Hellenic said in a statement. It did not elaborate when the shutdown would take place or how long it would last.
The problem concerns small fractures and a distortion on the hull of the unit's gasifier, Hellenic said, adding there was no danger to staff or the environment.
Hellenic's announcement follows complaints by Greek opposition lawmakers who expressed concerns over the incident. Earlier on Wednesday, a Greek prosecutor ordered a preliminary investigation into the complaints.
Elefsina's flexicoker has a production capacity of 20,000 barrels per day.
Elefsina, which also has a hydrocracker unit, is one of Hellenic's three Greek refineries. Elefsina was upgraded in late 2012 at a cost of about 1.4 billion euros ($1.9 billion) to produce higher-value petroleum products that can be sold abroad and reduce Hellenic's dependence on its recession-struck domestic market.