Circle Internet Financial, once one of the best-funded early bitcoin startups, has announced it will no longer allow customers to buy and sell the digital currency.

Confirmed today via an announcement in The Wall Street Journal and first revealed last night in a customer update, Circle said it will now focus on using a soon-to-be-launched proprietary blockchain-based protocol called Spark.

Customers can continue to store bitcoin using the Circle app, however, those who want to buy and sell digital currency will be directed to digital asset exchange service Coinbase, once one of Circle's biggest competitors in the brokerage space.

Users can still convert bitcoins stored via the service to dollars, pounds or euros and continue sending money via social messaging, without fees. But notably, users will no longer be able to send money to other bitcoin addresses.

Despite the changes, Circle maintained that its vision is unchanged, even if the technology it uses will shift.

A blog post issued today reads:

Currently available in the US, UK and some European countries, the introduction of Spark extends the company's service to The Philippines and Korea, via partnerships with startups Korbit and Coins.ph.

In total, Circle has raised $136m, according to data from Crunchbase, most recently raising $60m in a Series D funding round in June that also saw it expand its operations to China.

Disclaimer: CoinDesk is a subsidiary of Digital Currency Group, which has an ownership stake in Circle.

Scissors image via Shutterstock