NEW YORK - The return of Billy Crystal helped boost viewership for the Academy Awards in the U.S., although the ratings didn't budge in Canada.

The Nielsen Co. estimated that 39.3 million people watched the Oscars on ABC Sunday night in the U.S., up from the 37.9 million viewers during the much-panned 2011 show where James Franco and Anne Hathaway shared hosting duties.

In Canada, CTV said 6.1 million viewers watched the awards show, which just about matched last year's tally. The ratings peaked at just over 7 million when Canadian Christopher Plummer took to the stage to accept his best supporting actor award, CTV said.

Crystal was called in to host the show after Eddie Murphy pulled out. It was the ninth time Crystal has done that job and he delivered, despite worries that best picture winner "The Artist" would not be much of an audience draw.

But the Oscars could not top the ratings for the Grammy Awards in the U.S.

Nielsen said 39.9 million people watched the Grammys on CBS on Feb. 12. That huge audience was likely due to the popularity of big winner Adele and curiosity about how Grammy producers would address the death of singer Whitney Houston the day before the show.

It was only the second time since the two events were televised that the Grammys earned a bigger audience in the U.S. than the Oscars. After the Super Bowl, the Oscars are frequently the second most-watched TV event of the year.

In 1984, when Michael Jackson was the big winner at the Grammys, the show had 51.7 million viewers. The Oscars that year, when "Terms of Endearment" won best picture, had 42.1 million viewers, Nielsen said.

The social media analysis company Trendrr estimated that there were some 4.2 million examples of social media action during the Oscars on Sunday -- such as tweets on Twitter and posts or likes on Facebook.

That more than doubled the 2.02 million estimate from last year's Oscars, Trendrr said. It illustrates the growth in social media as well as the tendency of people to comment online with their friends as they share the experience of watching on TV, said Chris Thonis, spokesman for Trendrr.

Still, it paled in comparison with the 17.47 million examples of social media activity during the Super Bowl earlier this month, and the 17.12 million for the Grammys, he said.

The Grammys have become more of a performance show than an awards show in recent years, increasing their television ratings and giving viewers plenty to talk about.

"There were great story lines for the Grammys this year versus the Oscars, which didn't have as many story lines," Thonis said.