NEW YORK — Motorola is updating its low-cost smartphone, the Moto E, as it targets first-time smartphone buyers worldwide.

Among the improvements over last year’s model: The camera now has auto-focusing, whereas the older model had a fixed-focus lens that didn’t compensate for how far away the subject was. The new Moto E will also have a front-facing camera for selfies, though images won’t be as sharp as the 5 megapixels on the rear. There’s also a model with 4G cellular connectivity. Last year’s model was available only for slower, 3G networks.

In the U.S., Motorola will target prepaid customers, as well as those looking to buy children their first smartphones. The 4G model will cost $150 in the U.S., while the 3G will go for $120, both without contract requirements. The screen measures 4.5 inches diagonally, slightly larger than before.

Chicago-based Motorola, which Lenovo Group bought from Google Inc. in October, has been trying to set itself apart from other phone makers by selling cheaper phones that have some features found in higher-end products. For instance, all of its phones use Corning’s Gorilla Glass for durability.

“Even in developed markets, a large percentage of the population isn’t on a smartphone,” Rick Osterloh, Motorola’s CEO, said in an interview. “This category represents the biggest growth area.”

Motorola announced its new phone Wednesday ahead of next week’s Mobile World Congress in Barcelona, Spain. Samsung, HTC and others are expected to unveil their spring lineups at the show. Sony also announced a budget phone this week for $146, though there’s no plan to sell it in the U.S. LG announced four mid-range smartphones. Details on prices and U.S. availability weren’t immediately revealed.