Methanex New Zealand has restarted its second methanol plant at its Motunui site in Taranaki.
The Vancouver-based company says the plant will raise capacity at the site by 650,000 tonnes per year to 1.5 million tonnes per year.
Managing director Harvey Weake says the plant was mothballed for nine years because of a lack of gas to feed it.
However additional reserves have come into the market and the company has been able to secure sufficient gas to underwrite the investment in restarting the plant.
Almost all the methanol will go China, Korea, Japan and Taiwan, and very little to the Australian and New Zealand market.
Mr Weake says it's taken six months and cost about $100 million to open up the plant again, and the restart has created 40 to 50 jobs.