The Ultrabooks also have some additional features that the Sleekbooks don't, Conrad said. The Ultrabooks boot more quickly, have antitheft features typically baked into Intel's latest Core processors, and can also resume from standby more quickly.

Intel in the past has said Ivy Bridge ultrabooks will also blend in tablet-like features such as touchscreens, but HP officials declined comment on when such models would be introduced.

The Envy Sleekbooks come in screen sizes of 14 inches ($699.99) and 15.6 inches ($599.99), and will ship worldwide starting on May 9. The Envy Ultrabooks come in screen sizes of 14 inches ($749.99, available on May 9) and 15.6 inches ($799.99, available on June 20).

HP also announced additional ultrabooks for consumers and enterprises with screen sizes between 11.6 inches and 14 inches.

HP's new Envy Spectre XT is a 13.3-inch ultrabook that is only 14.5 mm thick and weighs only 1.4 kilos. The laptop has 128GB of storage and a choice of Intel's third-generation Core processors. The ultrabook will offer seven hours of battery life, and will become available in the U.S. on June 3 starting at $999. HP declined to comment on worldwide availability.