* Conservatives secure convincing majority; in power since 1971
* Province is biggest foreign energy supplier to United States
* Rival shares philosophies with U.S. Tea Party movement (Adds quotes from leaders, details)
HIGH RIVER, Alberta, April 23 (Reuters) - Alberta's Progressive Conservative Party fended off its biggest challenge in more than four decades of rule on Monday, winning a convincing majority as voters balked at handing Canada's top energy-producing province to an upstart right-wing movement that promised traditional values and fiscal restraint.
The ruling party of Premier Alison Redford was winning or leading in 59 of 87 voting districts in the western province of 3.8 million people, garnering 44 percent of votes cast.
Its biggest challenger, the Wildrose Party led by Danielle Smith, was leading or elected in 21 districts and had 35 percent of the vote.
It was a battle of two right-of-center visions in the province that is the largest foreign energy supplier to the United States, and a growing economic force within Canada.
Wildrose had promised to pay out a slice of the province's oil and gas revenue to residents and limit participation in some federal programs, while Redford's PCs - now one of the country's lon gest-ever pol itical dynasties - promised to increase Alberta's role within the country.
"Every Albertan knew that this election was about choice," Redford said in her victory speech. "A choice to put up walls or build bridges ... Tonight Alberta chose to build bridges."
The Wildrose, who are further to the political right than the Progressive Conservatives and share many political philosophies with the U.S. Tea Party movement, had led in the polls. But the party suffered after two candidates made intemperate comments about sexual orientation and race.
"I acknowledge that we wanted to do better, and we expected to do better. Am I surprised? Yeah. Am I disappointed? Yeah. Am I discouraged? Not a chance," said Smith, who had the support of many of Prime Minister Stephen Harper's campaign workers.
"Albertans have decided that Wildrose might need some time, might need some time to prove ourselves, might need some time to establish ourselves. I relish the opportunity."
The Conservatives have ruled in Alberta since 1971, led by five leaders, the latest being Redford, a 47-year-old lawyer and former justice minister. A series of scandals, deficit budgets and policies that angered the powerful oil patch lobby led to a break in the right-wing vote. However, Wildrose did not prove in the end to be a threat to the PCs' reign.
"It says the PC brand is maybe the strongest brand in Canadian political history," Rod Love, who was chief of staff for former Conservative Premier Ralph Klein.
"It can take a ton of hits and body shots, and after 41 years, Albertans still respond to the brand."
Alberta is not Canada's most populous province, but it is the richest. It derives about a third of its revenue from its vast reserves of oil and gas.
Its oil sands deposits rival conventional oil reserves in Saudi Arabia and Venezuela, and Redford's government is trying to convince Washington to approve the $7 billion Keystone XL pipeline, which would carry Alberta's oil sands-derived crude to Texas.
TOLERANCE BECAME ISSUE
Starting out as a protest movement, Wildrose pushed for smaller government, recall votes and traditional values. Its leader, Smith, 41, is a former property-rights advocate and newspaper columnist.
She raised eyebrows by not taking major issue with comments by some of her candidates, including one who said gay people would be subjected to a lake of fire on judgment day and another who said that he would be able to speak more effectively to all ethnic groups because he is Caucasian.
Smith angered environmentalists by saying that the science of climate change was not settled and that government money is wasted on such initiatives as carbon capture and storage.
Duane Bratt, political scientist at Mount Royal University in Calgary, said it was stunning that so many opinion polls were wrong, leading to early speculation that voters changed their minds in the voting booth.
"I think that's a legitimate question - did people just kind of pause and say, 'What do we really know about Wildrose?'" he said. (Reporting by Jeffrey Jones and Scott Haggett; Editing by Eric Walsh and David Brunnstrom)