LOS ANGELES -- "Avatar" and "The Hurt Locker" have been duking it out all awards season, and now the two films face their final showdown: They enter the 82nd annual Academy Awards prizefight with nine nominations apiece.

The films -- which, coincidentally, were directed by former husband-and-wife James Cameron and Kathryn Bigelow -- couldn't be more different.

"Avatar" is an eye-popping 3-D science-fiction studio extravaganza. It is the most expensive film ever made and has gone on to be the most successful film ever, earning more than $2 billion so far worldwide.

"The Hurt Locker" is a gritty, low-budget, independent film about a bomb-disposal unit in the Iraq war. Though it has earned plenty of accolades this awards season, it has yet to crack the $13 million mark at the box office.

The films are two of the best-picture nominees announced Tuesday by the Academy of Motion Picture Arts & Sciences, among an eclectic mix that includes another sci-fi hit, "District 9," another war film, "Inglourious Basterds" and the animated hit "Up," which is only the second animated film ever to receive a nod in this category.

Though it was no surprise that "Precious: Based on the Novel 'Push' by Sapphire" and "Up in the Air" earned best-picture nods, there were some unexpected choices, including "The Blind Side," "An Education" and "A Serious Man."

The academy's announcement marked the first time in 66 years that there were 10 nominees in this marquee category, instead of the traditional five.

The nominees for best director are Cameron for "Avatar," Bigelow for "The Hurt Locker," Lee Daniels for "Precious," Quentin Tarantino for "Inglourious Basterds" and Jason Reitman for "Up in the Air."

In the acting categories, the academy followed in the footsteps of the Golden Globes and the Screen Actors Guild Awards. The only real surprise was Maggie Gyllenhaal for best supporting actress for "Crazy Heart." She had largely been overlooked this awards season.

The nominees for best actress are Sandra Bullock for "The Blind Side," Helen Mirren for "The Last Station," Carey Mulligan for "An Education," Gabourey Sidibe for "Precious" and Meryl Streep for "Julie & Julia."

With this nod, Streep has earned an unprecedented 16 Oscar nominations over the last 31 years. She has received two Oscars, best supporting actress in 1979 for "Kramer vs. Kramer" and best actress in 1982 for "Sophie's Choice."

The best actor nominations went to Jeff Bridges for "Crazy Heart," George Clooney for "Up in the Air," Colin Firth for "A Single Man," Morgan Freeman for "Invictus" and Jeremy Renner for "The Hurt Locker."

Joining Gyllenhaal in the best supporting actress category are Penelope Cruz for "Nine," Vera Famiga and Anna Kendrick for "Up in the Air" and Mo'Nique for "Precious." Cruz won in this category last year for "Vicky Cristina Barcelona."

Nominated for best supporting actor are Matt Damon for "Invictus," Woody Harrelson for "The Messenger," Christopher Plummer for "The Last Station," Stanley Tucci for "The Lovely Bones" and Christoph Waltz for "Inglourious Basterds."

The nominations were revealed at the Samuel Goldwyn Theater in Beverly Hills, with last year's lead actress nominee Anne Hathaway helping Oscar president Tom Sherak with the announcements.

The Oscars will be telecast live March 7 on ABC from the Kodak Theatre in Hollywood.

Besides increasing its nomination list for best picture, the academy also is featuring two hosts at the Oscar ceremony, Alec Baldwin and Steve Martin, who starred together in "It's Complicated."