SAN FRANCISCO — PayPal said on Friday that it had pulled out of the coalition of companies involved in a Facebook-backed cryptocurrency initiative, in the latest headache for the social network’s effort.

The proposed cryptocurrency, Libra, has been in the works at Facebook for more than a year and was announced to much fanfare in June. Libra was designed to function as a cryptocurrency that could be freely traded inside Facebook’s properties, like Messenger and WhatsApp, and would be used for international exchange. At the time, Facebook said more than 27 corporate partners — including PayPal, Visa, Mastercard and companies like Uber — had pledged to support the project.

“PayPal has made the decision to forgo further participation in the Libra Association at this time and to continue to focus on advancing our existing mission and business priorities,” a spokeswoman for PayPal, Amanda Coffee, wrote in an email on Friday.

A Facebook spokeswoman did not respond to a request for comment. PayPal’s move was earlier reported by The Wall Street Journal.