Home Box Office has elbowed Showtime to grab pay TV rights to TriStar theatricals for an exclusive five-year term, beginning in the year 2000, when the studio’s Showtime contract expires.

That’s the word from sources, who say that, as part of the same transaction, HBO has added five years to its current five-year deal with Columbia Pictures, giving the pay cabler exclusive rights to Col’s theatricals through 2004.

The extension with Columbia and the new contract with TriStar could result in HBO funneling about $1.5 billion into Sony’s coffers.

The box office performance of the Columbia and TriStar movies will play an important role in how much HBO ends up paying Sony for their pay TV rights.

Sources say HBO will pay about 30% of the final theatrical-rental figure of each movie, with undisclosed caps at the high end and the low end.