Play was suspended at the Italian Open on Friday because of rain after less than an hour of play.
Officials said play would not restart until at least 11 a.m. EDT on the waterlogged Castello di Tolcinasco course.
Overnight leader Joakim Backstrom of Sweden, whose 10-under 62 broke the course record by one stroke, and Markus Brier of Austria, who shot a 63, were among the late starters.
Taichi Teshima of Japan, who opened with a 64, bogeyed the second hole and was among those tied for third at 7 under, along with England's Richard Finch.
Finch, who tied for second two years ago, birdied his opening hole and then made two pars before the players were called off the Castello di Tolcinasco course after less than an hour of play.
Philip Price, a former member of Europe's Ryder Cup team, withdrew with a wrist injury, and American Notah Begay pulled out with a recurring back problem.