PARIS Hilton’s haunches or Jessica Biel’s butt?

City women are flocking to plastic surgeons in search of a booty befitting their favorite starlet.

At one new Upper East Side clinic, posterior patients can request a specific celebrity’s backside. Popular requests include Eva Longoria, Lindsay Lohan, Jessica Simpson, Paris Hilton and Jessica Biel.

Noticeably absent from the list is a certain Bronx-born booty bombshell, Jennifer Lopez.

The new rear to bear is smaller, tighter and “more refined,” according to Dr. Brad Jacobs, who’s unveiling his “Star Butts” clinic today in his office.

Surgeons re-create famous fannies by transferring patients’ unwanted belly flab or saddlebags to their bottoms.

Dr. Jacobs said he can turn even the flattest rump into a celebworthy humps with a little help from your extra padding and about $11,000. “It’s your own fat, and it’s in the best soil [your butt], so it lasts,” said Jacobs. “The added bonus is they’re getting liposuction to get the excess fat and put it where you need it,” he said.

American Society of Plastic Surgeons statistics show that butt lifts have increased dramatically, up 283 percent from 2000 to 2005.

Business is certainly booming at some Big Apple offices.

“We’re doing four, maybe five a week on a busy week,” said George Lefkovits, of Manhattan. “It’s now become one of our key operations in the office.

“You can do this on a Thursday or a Friday and be back to work on Monday,” Lefkovits said.

Some complications can include infection, lumpiness and unevenness. Critics also contend that the fat doesn’t stay in the posterior for long, and most people will need to be retouched as time passes.

Carla Murino, a new bride from Staten Island, has had her new bottom for a year and is loving every curve of it.

“I didn’t want to look like JLo,” said Murino, a patient of Jacobs. “It’s more like I wanted an athletic butt – nice, little and perky.” And that’s what she said she got over a year ago when she fat removed from her stomach to her bottom.

“It’s great,” she said. “I put on yoga pants and its like, I have a butt!”

Rump change

If you don’t have a bazillion dollars to resculpt your rear, here are some other, cheaper bum optimizers.

* The squat – The single best exercise for strengthening, toning and shaping the butt. Just stand with your feet shoulder-width apart, bend at the knees until you’re parallel to the floor, push through your heels, contracting your bum. Repeat.

* Padding – If you lack rear assets, the Better Bottom ($39) is a panty with padding to resemble a realistic round bottom. If you’ve got enough padding of your own, but want a more contoured shape, try the Booty Booster ($16; both available at lovefifi.com).

* Clarins Total Body Lift – This is the cellulite-reducing cream everyone says actually works. Aromatic plant and caffeine extracts help decrease fat storage, improve circulation and firm the skin. Apply twice a day ($57; available anywhere Clarins is sold).

– Marina Vataj