* 'KPop Demon Hunters' named best animated feature

* 'Sinners' and 'One Battle After Another' vie for best

picture

* Chalamet, DiCaprio, Jordan among best-actor nominees

* Security tight amid Iranian threat warning

(Updates with additional winners, paragraphs 1-8)

By Lisa Richwine

LOS ANGELES, March 15 (Reuters) - An absent Sean Penn

and the hit movie "KPop Demon Hunters" were celebrated at the

Academy Awards on Sunday as Hollywood toasted the year's best

performances in the movie business.

Penn was named best supporting actor for his role as an

obsessed military officer in the darkly comic thriller "One

Battle After Another," one of the movies vying for the top prize

of best picture. It was the third Oscar for Penn, who frequently

skips movie industry awards shows and was not in the Dolby

Theatre audience.

"Sean Penn couldn't be here, or didn't want to, so I'll

accept the award on his behalf," said presenter Kieran Culkin,

last year's supporting actor winner.

The 75-year-old Amy Madigan was named best supporting

actress for her role as the wacky Aunt Gladys in horror film

"Weapons." She earned her first Oscar 40 years after her first

Oscar nomination.

In her remarks, Madigan thanked "Weapons" director Zach

Cregger.

"He just wrote a dream part and he just let me grab it by

the throat," Madigan said.

"KPop Demon Hunters," a Netflix ( NFLX ) movie that became a

global phenomenon, was named best animated feature.

Paul Thomas Anderson, the writer and director of "One

Battle" and a 14-time Academy Award nominee, earned his first

Oscar midway through Sunday's show for best adapted screenplay.

He dedicated the honor to his family, "the people who know what

it's like to live with a writer."

Host Conan O'Brien opened the show by joking that he was

honored to be "the last human host" of the awards at a time when

Hollywood is worried about artificial intelligence taking over

jobs.

On a serious note, O'Brien said he hoped the show would

offer a sense of optimism. He noted that nominees hailed from 31

countries on six continents.

"Let us celebrate not because we think all is well but

because we work and hope for better," O'Brien said.

SECURITY TIGHTENS AROUND DOLBY THEATRE

The glitzy celebration, Hollywood's most over-the-top gala

of the year, took place as the U.S. wages war on Iran.

Security was tight in and around the ceremony. Organizers

said they were working closely with the FBI and Los Angeles

police after a federal warning of a possible Iranian threat

against California, though authorities have cited no specific or

credible danger to the Academy Awards. Attendees had to cross

through several traffic checkpoints and go through metal

detectors to make their way into the event.

The ceremony featured an unusually unpredictable best

picture race between vampire story "Sinners," which went into

the night with a record 16 nominations, and "One Battle After

Another." The show was televised live on Walt Disney's ( DIS )

ABC and streamed on Hulu.

The festivities masked the unease in the film business over

where movies are being made as studios chase tax incentives and

lower costs elsewhere in the U.S. and overseas, weakening

Hollywood's grip on production.

Warner Bros., the studio behind "One Battle" and

"Sinners," is in the process of being sold to Paramount Skydance ( PSKY )

in a deal that will narrow the ranks of major film

distributors. A media watchdog group, Free Press, circulated a

roving billboard around Hollywood over the weekend airing its

opposition to the merger.

Workers in front of and behind the camera are worried

artificial intelligence will limit job opportunities and stifle

creativity and risk-taking.

AN UNPREDICTABLE RACE FOR BEST ACTOR

The race for best actor was an especially unpredictable one,

pitting Timothée Chalamet against Leonardo DiCaprio and Michael

B. Jordan.

Chalamet had been considered a frontrunner for his acclaimed

performance as a ping-pong hustler in "Marty Supreme," but his

prospects seemed to dim over an awards-season campaign featuring

a streetwear line and a giant blimp and remarks dismissing

ballet and opera.

"One Battle After Another," starring DiCaprio as a one-time

political radical now parenting a teenager, was seen as the

frontrunner for best picture after stacking up trophy after

trophy at recent ceremonies.

But "Sinners," a celebration of blues music and Black

culture in the Segregation-era U.S. South starring Jordan, made

a late surge with a win this month at the Actor Awards.

Winners of the gold Oscar statuettes are chosen by the

roughly 10,000 actors, producers, directors and ‍film

craftspeople who make up the Academy of Motion Picture Arts and

Sciences.

The Academy took steps this year to try to ensure voters

have actually watched the movies they are voting on. The online

balloting system for the first time tracks whether a voter has

streamed each movie. Voters, however, can check a box to say

they watched the movie elsewhere outside the Academy website.