Actress Anne Hathaway, left, and Academy of Motion Picture Arts and Sciences president Tom Sherak on Tuesday announced the best actor nominees for the 82nd Academy Awards in Los Angeles. (Kevin Winter/Getty Images)The Canadian filmmakers behind two of this season's most buzzed about films are leaders in the race for Oscar this year, with James Cameron's Avatar and Jason Reitman's Up in the Air earning multiple nods, including for best picture.

The 82nd annual Oscars nominations were announced in Los Angeles on Tuesday morning, with Kapuskasing, Ont.-born Cameron's 3-D blockbuster Avatar tied with ex-wife Kathryn Bigelow's gritty Iraq drama The Hurt Locker at nine nominations each.

This year, there are 10 contenders for the coveted best picture Oscar. They are:

• A Serious Man.
• Avatar.
• An Education.
• District 9.
• Inglourious Basterds.
• Precious, Based on the Novel Push by Sapphire.
• The Blind Side.
• The Hurt Locker.
• Up.
• Up in the Air.

For the first time in more than six decades, the Academy of Motion Picture Arts and Sciences named 10 nominees instead of the traditional five for its top category.

Expanding the field is a move to broaden the range of titles in contention, from populist fare to the smaller, more challenging titles typically favoured by Academy voters.

James Cameron's eye-popping, sci-fi epic Avatar scored a co-leading nine Oscar nominations. (Twentieth Century Fox) Cameron's sci-fi epic Avatar, which has soared to the top of the box office and smashed a raft of international records (set by his earlier film, Titanic) since its release late in December, leads nominees along with The Hurt Locker, Bigelow's intense drama about a bomb-defusing team.

Fantastical, revisionist Second World War tale Inglourious Basterds is up for Oscars in eight categories.

Montreal-born Reitman's Up in the Air, his corporate downsizing comedy-drama, matched urban coming-of-age story Precious with six nominations.

These five films also figure into the race for best director, with Lee Daniels and Quentin Tarantino (for Precious and Inglourious Basterds, respectively) vying against Cameron, Reitman and Bigelow.

Only the fourth woman to earn a best director nomination (after Sofia Coppola, Jane Campion and Lina Wertmuller), Bigelow has nonetheless developed a winning record at other award ceremonies this month.

Though Avatar snagged the Golden Globe for best dramatic film, The Hurt Locker won the top honour from both the Directors Guild of America (whose recipient typically goes on to earn the best director Oscar) and the Producers Guild of America. It was also tapped by many critics groups as 2009's best film.

Performances honoured

In the quest for best actress this year, two fresh new faces are up against two of the industry's most celebrated figures and America's sweetheart.

Newcomer Gabourey Sidibe, right, along with musician-actor Lenny Kravitz, is a best actress nominee for her title role in the coming-of-age drama Precious. (Anne Marie Fox/Maple Pictures)Carey Mulligan's precocious schoolgirl in An Education and Gabourey Sidibe's illiterate teen in Precious will compete for the Oscar against Meryl Streep's pitch-perfect turn in Julie & Julia as cooking icon Julia Child, and Helen Mirren's portrayal of Sofya Tolstoy in The Last Station.

Sandra Bullock, a regular of romantic comedies, scored a nomination for her role in the sports drama The Blind Side.

This year's best actor nominees face tough competition, with each having earned kudos for their roles, including Jeff Bridges as a down-and-out musician attempting a comeback in Crazy Heart and George Clooney's corporate downsizer undergoing a personal crisis in Up in the Air.

Colin Firth has won praise for his turn as a depressed, gay professor in A Single Man, while critics have lauded Jeremy Renner's reckless bomb-defusing expert in The Hurt Locker. Morgan Freeman, who drew on his personal relationship with Nelson Mandela to embody the former South African leader, seemed born to play him in Invictus.

Both Jeff Bridges and Maggie Gyllenhaal are nominated for their performances in Crazy Heart. (Lorey Sebastian/Fox Searchlight) Mo'Nique and Christoph Waltz — who each portrayed monstrous characters (a violently abusive mother in Precious and a sadistic Nazi officer in Inglourious Basterds, respectively) — have dominated the supporting actor categories at the majority of the season's award shows. They naturally scored Academy nominations as well.

Mo'Nique's best supporting actress competition includes both Vera Farmiga and Anna Kendrick from Up in the Air, Penelope Cruz from the big-budget musical Nine, and Maggie Gyllenhaal as a single mom and music journalist in Crazy Heart.

Waltz faces Toronto-born stage and screen star Christopher Plummer's Leo Tolstoy (The Last Station), Matt Damon as a post-apartheid rugby captain in Invictus and Woody Harrelson's turn as a sort of herald of military deaths in The Messenger. Stanley Tucci, as a murderous neighbour in The Lovely Bones, rounds out the best supporting actor category.

Animated and foreign films

Auteur Michael Haneke's disturbing, acclaimed film The White Ribbon is nominated for best foreign film and for its cinematography. (Films du Losange/Sony Pictures Classics/Mongrel Media)Two films that first dazzled world audiences at the 2009 Cannes film festival — and much celebrated ever since — were shoo-ins as best foreign film nominees: Germany's The White Ribbon (which won the Cannes Palme d'Or) and France's Un Prophète (which won the Cannes Grand Prix).

Israeli film Ajami, set in a mixed Jewish-Arab area and blending together a handful of different stories, is also nominated, along with a pair of movies from South America: Peru's The Milk of Sorrow, the Golden Bear winner at the Berlin International Film Festival, and Argentine thriller El secreto de sus ojo (The Secret in Their Eyes).

The contest for best animated film will pit 3-D blockbusters Up and Coraline against the traditionally drawn The Secret of Kells and The Princess and the Frog. Also nominated is the quirky stop-motion Fantastic Mr. Fox.

The 82nd annual Academy Awards, hosted by Steve Martin and Alec Baldwin, will be presented March 7 at Hollywood's Kodak Theatre.

With files from The Associated Press and Canadian Press