Led by former finance minister Anwar Ibrahim, the opposition is aiming to build on startling electoral gains in 2008, when the Barisan Nasional, or National Front, ruling coalition lost its customary two-thirds parliamentary majority.

The result signaled a breakdown in traditional politics as minority ethnic Chinese and ethnic Indians, as well as many majority Malays, rejected the National Front's brand of race-based patronage that has ensured stability in the Southeast Asian nation but led to corruption and widening inequality.

Election officials said they expected voter turnout in the country of 28 million people to be up to 80 percent, a record high in what could be the most closely contested election in 56 years of rule by the National Front coalition.

"I would like to see some change," said computer engineer Wardina Shafie, 31, after she cast her vote on the outskirts of the capital, Kuala Lumpur. "I think the opposition has a good chance of taking government. I only worry about voter fraud."

As polls closed at 5.00 pm (5:00 a.m. EDT), independent news site Malaysiakini was flooded with stories of suspected voter fraud carried out by the ruling coalition, raising the possibility that the opposition could dispute the result in the event of a narrow coalition victory.

There were widespread witness accounts that "indelible" ink, introduced by the government in response to demands for electoral reform, could be washed off voters' fingers easily, enabling some to cast ballots more than once.

The campaign heated up in recent days with Anwar accusing the coalition of flying up to 40,000 "dubious" voters, including foreigners, across the country to vote in close races. The government says it was merely helping voters get to home towns.

Officials expect the first results for 222 parliamentary seats and more than 500 state seats to start trickling in from 8.00 p.m. (1200 GMT).

Under Prime Minister Najib Razak, the blue-blood son of a former leader, the coalition has tried to win over a growing middle class with social reforms and secure traditional voters with a $2.6 billion deluge of cash handouts to poor families.

He can point to robust growth of 5.6 percent last year as evidence that his Economic Transformation Programme to double incomes by 2020 is bearing fruit, while warning that the untested three-party opposition would spark economic ruin.

"The victor or loser of this 13th general election will not be BN or the opposition PR. It will be Malaysia, its people and our children," Najib tweeted on Sunday before casting his ballot in central Pahang state, referring to the ruling and opposition alliances by their initials.

Najib, who is more popular than his party, has had some success in steadying the ship since he was installed as head of the dominant United Malays National Organisation (UMNO) in 2009.

Formidable advantages such as the coalition's control of mainstream media, its deep pockets and a skewed electoral system make it the clear favorite.

But a failure to improve on 2008's performance, when the National Front won 140 seats in the 222-seat parliament, could threaten Najib's position and his reform program. Conservative forces in UMNO, unhappy with his tentative efforts to roll back affirmative action policies favoring ethnic Malays, are waiting in the wings to challenge his leadership.

LAST CHANCE FOR ANWAR?

The election represents possibly the last chance to lead Malaysia for Anwar, a former rising UMNO star who was sacked and jailed for six years in 1998 following a feud with then prime minister Mahathir Mohamad, who remains an influential figure.

The 65-year-old former deputy prime minister says his corruption and sodomy convictions were trumped up. He received a new lease on political life last year when a court acquitted him of a second sodomy charge.

His alliance, which includes an awkward partnership between a secular ethnic Chinese party with an Islamist party, says it presents a viable alternative, given a record of governing in four states it took over in 2008.

It wants to break down a network of patronage that has grown up between UMNO and business tycoons. The alliance also pledges to replace policies favoring ethnic Malays in housing, business and education with needs-based assistance.

The opposition is riding a growing trend of civil-society activism, which has been most evident in a series of big street protests in recent years calling for reform of the electoral system and huge campaign rallies.

Election observers said at least 200,000 people turned up for rallies across the country late on Saturday in a last-minute push to support the opposition.

"One for all, all for one - regardless of color, creed, or religion," veteran politician Lim Kit Siang told a 6,000-strong crowd in southern Johor state, bordering Singapore. "We are all Malaysians, why let racial sentiments provoke us?"

Most people in the crowd were ethnic Chinese, who make up about 25 percent of Malaysians and who abandoned the ruling coalition in 2008. Maintaining momentum among ethnic Malay voters may be more difficult amid warnings from the National Front that they would be at risk from Chinese economic domination if the opposition won.

"I am comfortable with the current situation here," said a 62-year old Malay housewife after she cast her ballot in Johor. "I can't trust the opposition. I don't know them."