Citing severe market pressures, Tamoil has earlier planned to shutdown the refinery located in the Canton of Valais on the left bank of the Rhône.
However, the Canton of Valais suggested Tamoil to put the refinery up for sale, in order to save jobs, reported Reuters.
The Canton said in a statement that initial presentations have been made by the five bidders and the final offer will be submitted by 31 March.
The refinery has 90 storage tanks with a total capacity of 795,000 cubic meters of crude oil and products. It produces 55,000 barrels-per-day, accounting for approximately 20% of total oil products in Switzerland.
Collombey is one of the only two refineries in Switzerland.
