* Home quarantine on main island of Luzon for 1 month

* Duterte orders businesses to close to stop spread

* Says police, soldiers will arrest violators

* 72-hour window to leave country (Recasts after Duterte address, adds quotes, details)

By Martin Petty and Neil Jerome Morales

MANILA, March 16 (Reuters) - The Philippines announced strict home quarantine measures on Monday for half of its population, shut down transport networks and ordered businesses to close or operate remotely in a bid to quell rising coronavirus cases.

In a televised announcement, President Rodrigo Duterte said existing travel restrictions and containment measures were not enough to arrest the spread so it was time to lock down the country's main island to minimise social contact and allow health workers to move quickly to control the contagion.

Duterte told mayors to act decisively to enforce quarantines and said violators of the lockdown would be arrested by police and the military and faced jail.

"Make no mistake, we are in the fight of our lives," Duterte said.

"We are at war against a vicious and invisible enemy. One that cannot be seen by the naked eye. In this extraordinary war, we are all soldiers."

The measures, if implemented fully, would be among the strictest in place in Asia, as the country of 107 million people tries to contain an outbreak that has seen confirmed cases rise sharply to 142 - from only three cases 10 days ago - with 12 deaths.

The health minister said nearly 1,000 tests had been undertaken so far. The Philippines until March 7 had been six weeks without a confirmed case.

The home quarantine is an expansion of a lockdown of Metropolitan Manila that started last week and prescribed stringent immigration curbs, curfews, bans on public gatherings, social distancing, the shutting of malls and a halt to non-essential movements in and out of the city.

"I cannot go into a guessing game. I have to act. If there is already contagion and cases that need to be attended to, then the government can move faster," Duterte said.

"We are put on notice that it is really dangerous."

The government announced on Monday a 27.1 billion pesos ($524.8 million) package help fight coronavirus and provide help to those hit by economic losses.

The central bank on Monday said it might consider a 50 basis points policy rate cut at its meeting on Thursday to counter the economic impact.

Duterte said he had been assured there were sufficient food supplies and said private operators providing necessities, like supermarkets, pharmacies, health clinics, banks and utilities would stay open.

Anyone wishing to leave the country had 72 hours to do so, according to an official memo. Business process outsourcing firms and export businesses could continue to operate, under certain conditions.

Businesses would have to take a hit, Duterte said, and he urged the country's oligarchs to cooperate and ensure their workers were taken care of financially.

"You have to close down your business and that is an order because you will help in propagating the disease instead of helping," he said. ($1 = 51.64 pesos) (Additional reporting by Karen Lema; Editing by Peter Graff and Angus MacSwan)

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