A Roman Tale

When a Hollywood star's career is on the skids, she can go to pieces or to Italy. Which explains why 34-year-old Madeline Mandell, once billed as ""the American Venus,'' is consuming pasta on a terrace in Rome with ``Scandinavian screen goddess'' Astrid, ``Germany's sex symbol'' Helga and ``reigning Italian movie queen'' Cleo. Each of them is eager for a role in Boccaccio Volgare, a four-part film epic starring superstar and lovable klutz Umberto Cassini, but their ambitions are threatened by the wicked machinations of a British actress who wants all four female roles for herself. While these matters are being resolved, some predictable diversions are offered: tours of Rome (food and wine included) alternate with myriad sexual encounters of a sort that might make Boccaccio blush. Madeline eschews most of the latter and saves herself for a final fadeout in the arms of Umberto, who is about to become both her husband and co-star. Though film actress Baker's first novel has as much staying power as the lira, it is lively and affable. Baker seems to be prolific: her memoir, To Africa with Love (Nonfiction Forecasts, Feb. 28), is out this month. 40,000 first printing; $40,000 ad/promo; author tour. (May 15)