* Big boost for Russia as arms seller
* U.S. State Department says not concerned by deal
By Olesya Astakhova
GORKI, Russia, Oct 9 (Reuters) - Russia announced on Tuesday it has signed $4.2 billion in arms deals with Iraq, making it the largest weapons supplier to the Middle East country after the United States.
The deals, disclosed in a Russian government document issued at a meeting between Prime Minister Dmitry Medvedev and Iraqi Prime Minister Nuri al-Maliki, give Russia a big boost at a time when the future of its arms sales to Libya and Syria is uncertain.
Iraq had been all but off limits for Russia's defence industry after the U.S.-led invasion of 2003 which ousted Saddam Hussein, one of Moscow's biggest weapons customers.
President Vladimir Putin had vocally opposed the invasion and Moscow has struggled to claw back a share of the markets in energy, arms sales and infrastructure projects in Iraq.
"After the fall of Saddam Hussein, it looked like the country was lost forever" as a Russian arms customer, said Ruslan Pukhov, director of the Russian security and defence think tank CAST. "This is absolutely sensational."
The contracts will help Russia maintain its position as the world's second-biggest arms seller after the United States, Pukhov said.
In Washington, the U.S. State Department signaled it was not overly concerned by the Russian deal.
"Iraq overall has initiated some 467 foreign military sales cases with the United States. If all of these go forward, it will be worth over $12.3 billion, so obviously our own military support relationship with Iraq is very broad and very deep," State Department spokeswoman Victoria Nuland told a news briefing.
The contracts were signed during visits to Russia by Iraq's acting defence chief in April, July and August, the document showed. It gave no further details and the state agency in charge of the weapons trade could not be immediately reached.
The Russian newspaper Vedomosti reported late last month that contracts worth $4.3 billion were being agreed ahead of Maliki's visit. It said they included deals for 30 Mi-28NE combat helicopters and 42 Pantsir-S1 mobile rocket launchers.
A spokesman for Russia's state-controlled arms exporter, Rosvooruzheniye, said it never discusses content of arms deals.
The contracts comprised the third biggest package of deals for Russian arms sales since the 1991 Soviet collapse, after a $7.5 billion agreement with Algeria in 2006 and a $6 billion sale to Venezuela in 2009, CAST said.
Russia delivered about $13.2 billion in weapons last year, said Konstantin Makiyenko, an expert at CAST.
Pukhov said the Iraq deals showed the government there "is ready to pursue an independent foreign and defence policy", but that the United States could have tacitly supported them to appease Russia, which scrapped a deal to sell air-defence systems to Iran citing U.N. sanctions over Tehran's nuclear programme.
Russian officials also have said Russia lost about $4 billion in arms deals with Libya because of the fall of longtime leader Muammar Gaddafi, and the future of Russian sales to Syria is uncertain because of the conflict there.