* Famine now a real possibility for 2017 - UN aid chief O'Brien
* Yemen economy collapsing, imports dried up, malnutrition "rife"
* 7.3 mln people "don't know where their next meal is coming from"
* Saudi-led coalition imposes "strict restrictions" on ports
By Stephanie Nebehay
GENEVA, Feb 8 (Reuters) - The United Nations said on Wednesday that 12 million people in Yemen faced the threat of famine brought on by two years of civil war and the situation was rapidly deteriorating.
It appealed for $2.1 billion to provide food and other life-saving aid, saying that Yemen's economy and institutions are collapsing and its infrastructure has been devastated.
"If there is no immediate action, and despite the ongoing humanitarian efforts, famine is now a real possibility for 2017. Malnutrition is rife and rising at an alarming rate," U.N. emergency relief coordinator Stephen O'Brien told a news briefing.
"A staggering 7.3 million people do not know where their next meal is coming from," he said.
Yemen has been divided by nearly two years of civil war that pits the Iran-allied Houthi group against a Western-backed Sunni Arab coalition led by Saudi Arabia that is carrying out air strikes. At least 10,000 people have been killed in the fighting.
Nearly 3.3 million people - including 2.1 million children - are acutely malnourished, U.N. figures show. They include 460,000 children under age five with the worst form of malnutrition who risk dying of pneumonia or diarrhoeal disease.
About 55 percent of Yemen's medical facilities do not function and the health ministry has no operational budget, said Jamie McGoldrick, U.N. humanitarian coordinator in Yemen.
"Many of the people never make it to the feeding centres or the hospitals because they can't afford the tranport," he said.
"Many people die silent and unrecorded deaths, they die at home, they are buried before they are ever recorded."
In all, nearly 19 million Yemenis - more than two-thirds of the population - need assistance and protection, the United Nations said.
"Ongoing air strikes and fighting continue to inflict heavy casualties, damage public and private infrastructure, and impede delivery of humanitarian assistance," it said.
"The Yemeni economy is being wilfully destroyed," it added, saying that ports, roads, bridges, factories and markets have been hit.
Yemen's main port at Hodeida is badly damaged and lacks cranes for offloading, leaving 30 ships offshore at any time and delaying deliveries, McGoldrick said. The Saudi-led coalition imposes strict restrictions on the ports which it controls.
An estimated 63,000 Yemeni children died last year of preventable causes often linked to malnutrition, the U.N. Children's Fund (UNICEF) said last week.
"In Yemen, if bombs don't kill you, a slow and painful death by starvation is now an increasing threat," Jan Egeland, secretary-general of the Norwegian Refugee Council, said in a statement as the U.N. plan was launched.
(Reporting by Stephanie Nebehay; Editing by Tom Miles and Angus MacSwan)
"In Yemen, if bombs don't kill you, a slow and painful death by starvation is now an increasing threat," Jan Egeland, secretary-general of the Norwegian Refugee Council, said in a separate statement as the U.N. plan was launched.
A military coalition led by Saudi Arabia entered Yemen's civil war in March 2015 to try to reinstate President Abd-Rabbu Mansour Hadi after he was ousted from the capital Sanaa by the tribal Houthis, who are fighting in an alliance with troops loyal to former President Ali Abdullah Saleh.
The United States has sent the Navy destroyer USS Cole to patrol off Yemen's coast to protect waterways from Houthi militia aligned with Iran, U.S. officials last week, amid rising tension between Washington and Tehran.
Oxfam accused Britain and other powers backing the Saudi-led coalition of "political complicity" in the Yemen conflict.
"The UK Government's calculated complicity risks accelerating Yemen towards a famine, putting millions of lives at risk and making a mockery of their global obligations to those in peril," Mark Goldring, chief executive of Oxfam GB, said in a statement.
(Reporting by Stephanie Nebehay; Editing by Tom Miles and Tom Heneghan)