It's hard to imagine Barbra Streisand, Whitney Houston and Celine Dion sharing a shade of lipstick, let alone a concert stage, but Grammy-winning songwriter David Foster is giving it his best shot. Foster is talking with the trio about touring with opera star Andrea Bocelli. The extravaganza, "Three Divas and a Tenor," would be modeled after the "Three Tenors" shows starring Luciano Pavarotti, Placido Domingo and Jose Carreras. The divas and Bocelli could be even more profitable.

Foster is talking with the trio about touring with opera star Andrea Bocelli.

The extravaganza, "Three Divas and a Tenor," would be modeled after the "Three Tenors" shows starring Luciano Pavarotti, Placido Domingo and Jose Carreras.

The divas and Bocelli could be even more profitable. Foster hopes to have the foursome perform in a handful of cities, including New York, Las Vegas, Monte Carlo and Rio, insiders say. Each show would be broadcast on a pay-per-view special, followed by the CD, followed by the laserdisc, followed by — who knows? — the spaghetti sauce.

Of course, the salaries would be astronomical. But the potential pay-off could be enough for the stars' record companies — Houston is on Arista, Bocelli on Polygram, and Streisand and Dion are on Sony — to bankroll the tour.

There are stumbling blocks.

Streisand has told Foster she's intrigued. But, according to one source, "she wants to have final say over what gets sung." She is also deep into recording her next album of love songs, which she's likely to support with her own tour.

Bocelli, who dueted with Dion on Foster's song "The Prayer" at last week's Grammys, also is looking ahead at a crowded concert schedule.

A rep for Foster confirmed that negotiations with the divas "are in the works," but added, "it's too soon to talk about."