BY DAVID KRONKE >TV CRITIC

Ricky Gervais has created some hilariously wince-inducing moments for his iconic TV characters - "The Office's" David Brent and "Extras"' Andy Millman - but probably none more so than the scene that opens tonight's "Extras" series finale: Millman, one-time British comedy star, reduced to shlumping in an episode of England's "Celebrity Big Brother."

Gervais - who also co-wrote and co-directed "Extras" with Stephen Merchant (who hilariously essays Andy's inept agent) and was the dark-horse winner of this year's Emmy for Best Actor in a Comedy - excels in the comedy of the uncomfortable.

And watching Andy endure the execrable behavior of house guests who erroneously believe themselves worthy of entitlement is an exquisite moment.

If the rest of "Extras: The Extra Special Series Finale" had been as inspired, it would've been one for the ages. Alas, it descends into the sort of rote "be careful what you wish for" moralizing that defines so many tiresome celebrity biopics that it dilutes its more uproarious moments.

Still, celebrity cameos by Clive Owen, who, playing "himself," utterly and thoughtfully eviscerates Andy's pal Maggie (Ashley Jensen) and George Michael (who sends up his predilection for anonymous sex) keep it plenty lively.

"Extras" charted Andy's career, from a hapless movie extra to the star of his own (tragically compromised) sitcom, "When the Whistle Blows," itself the abject, "According to Jim" version of "The Office," with Andy playing a one-note character with nothing but a witless catchphrase to carry the show.

Tonight's finale follows Andy in his career after his sitcom's demise, as he tries, ineptly, to redefine his persona.

Fifteen years ago, "The Player" and "The Larry Sanders Show" introduced the notion of celebrities exposing Hollywood's self-absorption through parodying themselves. In the interim, that's become a cliché, though "Extras" found a fresh way of mining such material (episodes with Ian McKellen, Daniel Rad-

cliffe and David Bowie redefined the genre).

"Extras" may not signal the high-water mark in Gervais' career, but it'll keep you anxious to see what he'll be up to next.

David Kronke, (818) 713-3638 david.kronke@dailynews.com

review>

EXTRAS: THE EXTRA SPECIAL SERIES FINALE

>What: Ricky Gervais returns as Andy Millman, who must deal with the fact that he sold his soul for success and his subsequent failures.
>Where: HBO.
>When: 8:30 p.m. Wednesday, 11:50 p.m. Saturday, 4:30p.m. Dec. 23, 7:30 p.m. Christmas Day.
>In a nutshell: Some hilarious moments, as well as some predictable moments regarding "be careful what you wish for."