Total SA (NYSE: TOT) has launched the sale of its offshore gas fields in the Netherlands, a move that would mark the French energy giant's exit from Dutch upstream production after 55 years, industry and banking sources said.

The Paris-based company hired investment bank Jefferies in December to run the process that could raise $300 million to $400 million, according to the sources.

Total had no immediate comment and Jefferies declined to comment.

Total's platforms in the Netherlands are nearing the end of their life after gas reserves have dwindled in recent decades.

Many of the platforms will require dismantling, a process known as decommissioning, which could carry tax credits to the benefit of the owners, the sources said.

Total's production in the Netherlands was around 41 billion cubic feet of gas, or around 20,000 barrels of oil equivalent per day (boe/d) in 2017, down from 25,000 boe/d the previous year as a result of the natural decline of fields and the shutdown of two fields, according to its 2017 annual report.

Total, which started its Dutch activities in 1964, holds interests in 24 offshore production licenses, of which it operates 20.

Upstream production aside, Total has a 55% stake in the Zeeland refinery in the Netherlands. It also operates a gas and power wholesale business in the country.

Total, like many of its peers, has sold out of aging assets in the North Sea in recent years to focus on new developments. Smaller, often privately-owned companies, have progressively taken over many of the assets.