Lipstick on His Collar

``The week Hallie Porter made the cover of Time magazine, she found out her husband was sleeping with her best friend,'' begins this crackling novel about behind-the-scenes book biz maneuverings. Head of a high-powered publishing firm, Hallie is also betrayed professionally, since Other Woman Olivia Collins is her editor-in-chief. As the house Hallie works for, and then the one she founds, are both swallowed by a conglomerate, the two women compete for the Maxwell Perkins Prize; the mechanics of their rivalry are enthralling. Juggling sex and business complications with finesse, Villars ( Adam's Daughters ) redeems her formulaic plot with flexible and stylish characters: a heroine capable of stooping to conquer, a villainess who can be ennobled. The obligatory brand names surprise by being classic (Hinckley yachts, Sulka silks) rather than trendy, and include Visine, as though these glamorous people have real-life dimensions. A likely, deserving bestseller. First serial to Cosmopolitan; Literary Guild and Doubleday Book Clubs alternates. (Apr.)