Precious medals, valuable momentum and coveted Olympic berths will all be on the line this week at the world figure skating championships with skaters looking to lay down their markers ahead next year's Sochi Winter Games.

London, a southern Ontario university town just north of Detroit, will provide an off Broadway setting as skaters chase positive reviews from the judges and fans before stepping onto the Olympic stage at the Russian Black Sea resort in 11 months.

Competition begins on Wednesday and while no Olympic medals will be awarded this week the results will determine how many entries countries will get in Sochi for each of the four events; men's and women's singles, pairs and ice dance.

For top skaters like American ice dancers Meryl Davis and Charlie White, the worlds represent a chance to enhance their reputation and perhaps gain a slight edge on chief rivals Olympic and world champions Tessa Virtue and Scott Moir of Canada.

"It will be helpful to be able to say we are the reigning world champions heading into the Olympic year, especially since Scott and Tessa are the reigning Olympic champions," Charlie White told Reuters. "It doesn't hurt to have two world titles instead of one going into the Olympics."

Davis and White and Virtue and Moir have dominated the ice dance scene taking the top two spots at the last three worlds and Vancouver Olympics.

While the Americans had to settle for silver behind the Canadians at the 2010 Winter Games and again at last year's world championships, Davis and White have had the better of their good friends this season finishing in first ahead of their training partners at the Grand Prix finals and Four Continents.

"Our goal will be to secure three Olympic spots for next year," declared Moir. "As a country you always want to send as many athletes and make as many Olympians as possible.

"Tess and I would obviously like to be on top and that would go along way to achieving that goal."

Sporting Celebrity

The women's spotlight is certain to fall on South Korean Olympic champion Kim Yuna but not for her usual brilliance and artistry.

Kim makes her return to the world stage for the first time since 2011 and figure skating fans will be eager to see if she can still produce the magic that helped transform her into a global sporting celebrity.

Judges will also be watching for lingering signs of rust on Carolina Kostner after the reigning world champion from Italy sat out the entire Grand Prix season.

The layoff does not appear to have had any impact on the artistic Italian who signalled she is ready to take on all comers capturing a fifth European title in her return to competition in January.

Japan's Mao Asada, a twice world champion and 2010 Olympic silver medallist, arrives in London unbeaten in all competitions this season and appears back on top of her game after two years of mixed results.

Competing on home ice, two-time reigning world champion Patrick Chan should be the heavy favourite to complete a hat-trick of men's titles but the Canadian has lacked consistency this season leaving the gold medal up for grabs.

Alarm Bells

Bidding to become first skater since Russia's Alexei Yagudin (1998-2000) to claim three consecutive world titles, Chan's only victory this season came in January when he captured a sixth straight national title.

A second place finish at Skate Canada in October followed by an even more lacklustre third place at the Grand Prix final at the same Sochi arena that will host the Olympic competition next year set off alarm bells that all was not well in the Chan camp.

But Chan will not be surrendering his crown without a fight.

As part of his preparations the 22-year-old skater put himself through a sort of figure skating boot camp working with fitness guru Andy O'Brien, whose client list also includes the National Hockey League's top player Pittsburgh Penguins Sidney Crosby.

"It would be nice to ride that wave of winning a world championship all the way to Sochi," said Chan. "This is a real test for me."

Chan will have to be close to his best if he is to see off strong challenges from a trio of Japanese skaters, led by Daisuke Takahashi the 2010 world champion and Vancouver Olympic bronze medallist.

Javier Fernandez, the athletic Spaniard who flashed his credentials with a dominating display at the European championships, will also be a skater worth watching.

"It's true that I have already beaten the world champion this season but that was only one competition and Patrick Chan is a master on the ice," Fernandez told Reuters. "Of course I want to be first but my main goal is to be in the top five."

The pairs competition looks set to be a two horse race between four-times world champions Aliona Savchenko and Robin Szolkowy of Germany and European champions Tatiana Volosozhar and Maxim Trankov of Russia.

China's Pang Qing and Tong Jian, world champions in 2006 and 2010, should also figure in the medal mix.