* Kosovo votes under shadow of war crimes investigation
* Thaci bidding for third term as prime minister
* Voters angry over poverty, corruption
By Matt Robinson and Fatos Bytyci
PRISTINA, June 8 (Reuters) - Former guerrilla Hashim Thaci bids for a third term as prime minister of Kosovo on Sunday, under pressure from voters angry over poverty and corruption and a war crimes investigation that threatens to ensnare his former comrades-in-arms.
Some analysts expect the closest election race since Thaci presided over Kosovo's Western-backed secession from Serbia in 2008.
Frustration with Kosovo's progress since independence is running high among many of its 1.8 million people, who rank among Europe's poorest. Around a third of the workforce is unemployed. Corruption is rife.
"The result of this election is the most uncertain of any election so far in Kosovo," said political analyst Astrit Gashi.
Fighting back, Thaci's government raised public sector wages, pensions and social welfare benefits in March by 25 percent, and promised to do the same again every year if given a new four-year mandate. That covers 240,000 people.
"Now we have the foundations of the state, a stronger state, my partners and I will devote all our energy to implementing a new mission to develop Kosovo economically," he told Reuters last week during campaigning.
If he wins, Thaci, 46, will come under immediate pressure from the West to heed the findings of an investigation by a special European Union task force into allegations Kosovo's guerrilla army harvested organs from Serb prisoners-of-war and sold them on the black market during a 1998-99 war.
The task force is expected to issue its findings within weeks.
It was set up following an explosive 2011 report by Council of Europe rapporteur Dick Marty which pointed the finger at Thaci and other ex-rebels including four high-ranking members of the prime minister's Democratic Party of Kosovo (PDK) and candidates for parliament.
Thaci has dismissed the allegations as an outrage, a bid to tarnish the Kosovo Albanian fight for freedom that eventually won NATO air support.
The West wants a court set up abroad to hear the case, fearing a fair trial in Kosovo is impossible due to witness intimidation and a legal system riddled with graft. That will require changes to the law and constitution.
"We have nothing to hide from our friends and partners," Thaci told Reuters last week.
Thaci was one of the leaders of the Kosovo Liberation Army, which took up arms in the late 1990s to break free from the repressive rule of Serbia under then strongman Slobodan Milosevic.
NATO intervened in 1999 with 78 days of air strikes against Serbia, trying to halt the massacre and mass expulsion of Kosovo Albanians by Serbian forces waging a brutal counter-insurgency fight. Kosovo became a ward of the United Nations in 1999.
It declared independence almost a decade later and has been recognised by more than 100 countries, but not Serbia or its big-power backer Russia, which is blocking the young state's accession to the United Nations.
Kosovo's economy is forecast to grow by at least three percent this year, driven by construction and cash sent home by Albanians working abroad.
Even then, the growth is insufficient to create enough jobs to absorb the thousands of Albanians entering the workforce every year in what is Europe's youngest society.
"This government deserve nothing else but to be brought down," opposition LDK leader Isa Mustafa told a campaign rally on Thursday.
Opinion polls are not reliable, but suggest the PDK has a slight lead over the LDK, the Alliance for the Future of Kosovo (AAK) and the leftist, often anti-establishment Self-Determination party.
Polls open at 7 a.m. (0500 GMT) and close at 7 p.m. (1700 GMT). Preliminary official results are expected by midnight (2200 GMT). (Writing by Matt Robinson; Editing by Sophie Hares)