PHILADELPHIA — Yahoo said Wednesday that it is expanding its original offerings, partnering with Liquid Comics to offer motion-comics.

The two companies said they will make the first two titles — created by film directors Barry Sonnenfeld and Guy Ritchie — available online this summer through Yahoo Screen.

Motion comics blend elements of comic book art and animation, offering some movement and action but on a limited scale. They have gained ground and popularity in recent years as publishers experiment with the medium, which can be viewed online or on devices like tablets and iPads.

By partnering with Liquid Comics and focusing on animation, Yahoo is enhancing its premium original content, said Erin McPherson, vice president and head of video for Yahoo. Together with Tom Hanks’ new animated Web series, ‘‘Electric City,’’ “motion comics are the start of a unique animated offering on Yahoo,’’ McPherson said.

Sonnenfeld’s offering is ‘‘Dinosaurs vs. Aliens.’’ The director of the ‘‘Men In Black’’ films tells the story of aliens invading Earth in prehistoric times.

Ritchie, whose films include the recent ‘‘Sherlock Holmes,’’ will have his ‘‘Gamekeeper’’ transformed into a motion comic. It focuses on a groundskeeper whose life is turned upside down by mercenaries.