UPDATE 4-Armenian president wins re-election, exit poll shows
* Sarksyan had big lead in polls before vote
* Campaign tainted by assassination attempt on rival
* Police received 70 allegations of voting violations (Adds details of alleged violations, partial results)
By Hasmik Mkrtchyan
YEREVAN, Feb 18 (Reuters) - Armenian President Serzh Sarksyan won a new five-year term on Monday, an exit poll and initial results showed, in an election marred by allegations of fraud and the lack of a serious opposition challenge.
Police said they had received at least 70 reports of voting violations after a campaign in which one of the outside candidates was shot and wounded. The opposition Heritage Party said many ballots cast for opposition parties had been thrown out, but did not say whether it would challenge the result.
The president, 58, has vowed to sustain economic recovery in his landlocked South Caucasus country and said before the vote he would ensure stability after years of war and upheaval, although he has outlined no plans for big policy changes.
The continued peace of a region where pipelines take Caspian oil and natural gas to Europe is a concern for foreign investors and neighbours, especially as relations are fraught with fellow former Soviet republic Azerbaijan.
"I voted for the future of Armenia, for the security of Armenia, for the security of our citizens," Sarksyan said as he cast his vote at a polling station in the capital, Yerevan.
The exit poll by Baltic Surveys/The Gallup Organization, reported by Armenian television, put Sarksyan on 58 percent of votes cast. His nearest rival, U.S.-born Raffi Hovannisian, trailed on 32 percent.
With 82 polling stations out of a total of 1,988 counted, Sarksyan was leading with 68 percent of the vote, according to official Central Electoral Committee data. Final results are expected late on Tuesday.
The result, if confirmed, will strengthen Sarksyan's hold on Armenia, which borders Iran, Georgia, Turkey and Azerbaijan, following his Republican Party's victory in a parliamentary election last year.
The immediate reaction on the streets of Yerevan was muted as voters awaited the official results. Opinion polls had long predicted Sarksyan would win after his biggest potential challengers opted not to run.
"I voted for Serzh Sarksyan to give him a chance and I will demand that he fulfils everything correctly as he promised," said Mariana, a housewife who declined to give her last name.
The exit poll was carried out among 19,130 voters at 122 polling stations. The Central Election Committee said more than 60 percent of the 2.5 million eligible voters cast their ballot.
"This is a victory of our society, in as much as the process of the election and the voting proved that democratic processes are irreversible in Armenia," said parliamentary vice-speaker Eduard Sharmazanov, a member of Sarksyan's party.
Sarksyan's promises of economic recovery resonate with voters in the country of 3.2 million, where more than 30 percent live below the poverty line. The average monthly wage is about $300 and unemployment was 16 percent last year.
"Sarksyan promotes the improvement of an educated society, which is a guarantee of Armenia's future," said Artak Avetsyan, 31, a teacher who came to cast his ballot for the incumbent.
But Sarksyan has given no indication he wants to change ties with neighbours, most notably Azerbaijan, which went to war over the disputed Nagorno-Karabakh region in the 1990s and uses its diplomatic and economic muscle to isolate Yerevan.
Nagorno-Karabakh is an ethnic Armenian-majority enclave inside Azerbaijan, which Armenia-backed rebels wrested from Azeri troops. Firefights along the border still kill troops on both sides.
Sarksyan, like many of his generation, is a veteran of the Nagorno-Karabakh war, and has accused Azerbaijan of threatening a new conflict. Baku denies it is the aggressor and says Armenia should hand back control of Nagorno-Karabakh.
Without a shift in regional politics, durable economic growth will be difficult for Armenia while its borders with Azerbaijan and Turkey remain closed. Turkey shut the border in 1993 in solidarity with its ethnic kin in Azerbaijan.
Most regional pipeline projects between growing regional power Turkey and the oil and gas-producing Azerbaijan isolate Armenia, making it more dependent on ties with its Soviet-era master Moscow, which maintains a military base on Armenian soil.
Election observers before the vote expressed concern over the democratic credentials of the election as none of Sarksyan's serious opposition rivals chose to stand. The last presidential election, in 2008, was marred by clashes in which 10 people were killed, but there were no reports of violence on Monday.
Observers will give their verdict on Tuesday. A police chief, Tatul Petrosyan, cited 70 reports of alleged voting violations and said two criminal cases had been opened.
Domestic security concerns were underlined by an attack on one of the candidates, Paruyr Hayrikyan, 63, an outsider in the election who was shot in the shoulder on Jan. 31.
Another dark horse in the race, Andrias Ghukasyan, went on hunger strike to press for Sarksyan's candidacy to be annulled.
A third candidate, Arman Melikyan, had said he would not vote because he believed the election would be skewed in Sarksyan's favour. Other potential rivals said they chose not to take part in the race for similar reasons.