"Lincoln" director Steven Spielberg (C) and cast members Daniel Day-Lewis and Sally Field pose during a photocall to promote the movie in Madrid January 16, 2013. [Photo/Agencies]

Voting for Sunday's Oscars, the highest honors in the movie industry, closed on Tuesday evening after a big spending campaign by Hollywood studios and the first online balloting system in the 85-year history of the Academy Awards.

More than 5,800 movie industry professionals who are members of the Academy of Motion Picture Arts and Sciences were invited to vote in 24 Oscar categories, starting on February 8 and ending at 5 pm PST on Tuesday (0100 GMT On Wednesday).

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The results will be tabulated at a secret location by accounting firm PricewaterhouseCoopers, who deliver the envelopes with the winners' names from backstage at the February 24 Oscars ceremony, televised live from Hollywood.

With the races for Best Picture, Director, Actress and Supporting Actor considered too close to call by awards pundits, movie studios have been blasting newspapers, radio, trade publications and television with promotions for their nominees.

The Los Angeles Times estimated that Warner Bros., the studio behind "Argo," and Walt Disney Co, which is distributing "Lincoln," had spent about $10 million each in Oscar campaigns in recent weeks. The two movies are locked in a tight contest for the top Oscar prize - Best Picture.

PricewaterhouseCoopers say there has never been a security breach in the secret voting in the 79 years it has worked with the Academy on the balloting process.