"They're not as mobile focused as Apple and Google are," Howe said in an interview. "They need to play catch up."
While the iPhone operating system is controlled exclusively by Apple, Google provides more flexibility with Android. Companies can take older versions of the software and customize it for their own services and preferences.
Zuckerberg has said he sees opportunities to push the company's features deeper into mobile devices. Already, Facebook, along with Twitter, has been built deeper into the latest version of Apple's software, enabling users to post easily to the social-networking service.
"I think people want it to be very integrated into all of the different devices that they have, and that's what we're going to focus on," Zuckerberg said on a call with analysts in January. "So, rather than just building an app that's a version of the functionality that you have today, I think making it so that we can just do — go deeper and deeper I think is going to be a big focus for us."
A new Facebook-enabled handset follows earlier forays into mobile devices for the social-networking service.
HTC began selling "ChaCha," an Android-based phone with a dedicated Facebook button to share music, photos and messages, in 2011. INQ Mobile Ltd. and Facebook that year also unveiled a phone with close integration of services, such as wall postings and photos.
While those devices have won over some die-hard Facebook fans, widespread adoption has been limited, according to Carolina Milanesi, an analyst at Gartner Inc. A new Facebook handset may struggle to match the success of devices made by Apple or Samsung Electronics Co., which manufactures the Galaxy line of phones, she said.
"I don't think that Facebook as a brand will necessarily get consumers — that are your average Facebook users — to pick out that phone over a Galaxy or an iPhone," she said.