AMSTERDAM, April 16 (Reuters) - The Dutch Senate on

Tuesday approved a law to permanently close the Groningen gas

field, following the government's promise that production will

never be resumed to limit seismic risks in the region.

Normal gas production at Groningen in the north of the

Netherlands ended last October after years of output cuts to

limit seismic activity linked to decades of extraction, that has

damaged thousands of buildings.

The gas field, once one of Europe's main suppliers, was

available for limited production during a cold snap in recent

months, but the government has proposed a law that would close

the field entirely by Oct. 1.

The law will leave huge reserves in the ground and has been

criticized by some politicians and gas industry advocates, who

argue doing so could jeopardize the country's security of

supply.

The Senate responded earlier this month by unexpectedly

postponing the final vote on the law, as several factions said

they needed more guarantees on supply.

That move angered the government, as Mining Minister Hans

Vijlbrief - who had been a strong advocate for the shutdown -

said he would resign if it would lead to a long delay and

ongoing seismic uncertainty for people living in the region.

Without the law, gas production could resume.

The field is operated by gas company NAM, a joint venture of

Shell and ExxonMobil ( XOM ), who have asked an

arbitration court to decide whether the Dutch state should

compensate them for the ending of gas production at Groningen.

Gas profits have delivered an estimated 363 billion euros

($385 billion) to the Dutch treasury since production started in

the 1960s, while Shell and Exxon's profit from Groningen was

around 66 billion euros during that period.

($1 = 0.9419 euros)