The Envy Sleekbook laptops, which have the latest chips from Advanced Micro Devices and Intel, come with 14- and 15.6-inch screens and start at US$599. HP's Envy Ultrabooks have the latest Intel third-generation Core chips, come with screens of the same size as the Sleekbooks, and start at $749.

The Envy Ultrabooks and Sleekbooks are no thicker than 19.8 millimeters, and weigh from 1.8 kilograms. The thin-and-light laptops' batteries last between seven and nine hours.

HP could not put AMD chips into its ultrabooks as the designs are exclusive to Intel, said Dean McCarron, principal analyst at Mercury Research. So HP built a separate laptop in Envy Sleekbooks for AMD chips.

Ultrabooks -- a new class of thin and light laptops backed by Intel -- come exclusively with Intel's processors and have been praised for design but criticized for high prices that can run over $800. AMD has said users don't need to pay a premium for ultrathin laptops, and that it wants to enable similar designs to ultrabooks with prices starting at $500.

HP's thin laptops come as Intel and AMD release faster chips that provide longer battery life. Intel has started shipping third-generation Core processors, aka Ivy Bridge, while AMD will soon announce new laptop and desktop chips code-named Trinity.