They are two of Hollywood's most famous stars, and now rumours are abuzz that the sexiest man on the planet George Clooney is romantically involved with buxom blonde Pamela Anderson.

The two stars sparked off rumours of a romance when they were spotted frolicking together on a fun dinner date.

According to reports, Clooney booked a private room at Sherman Oaks, California restaurant the Valley Inn, so that the he and Anderson could enjoy a quiet dinner without any intrusion on Jan 7 this year.

And from dinner, which ended with Pammie sitting on Clooney's lap, the two have been spending an increasing amount of time in each others company.

A pal revealed that both Clooney and Anderson are "determined" to keep their budding romance away from the tabloids for the moment.

"George and Pam have been determined to keep this one quiet," Contactmusic quoted the source, as saying.

While Clooney has dated the likes of Lisa Snowden, Renee Zellweger and Kelly Preston, Anderson's tastes run more into rock stars.

She recently split from husband Kid Rock last year (06) after a brief three month marriage, before which she was married to rocker Tommy Lee.