Government concerns about cryptocurrencies have snarled a plan by the owner of the New York Stock Exchange to launch the first futures contract that would pay out in bitcoin.

Intercontinental Exchange Inc., known as ICE, initially targeted November 2018 for the launch of the bitcoin futures, which it envisioned as a building block in a broader platform for trading and storing digital currencies. But the Commodity Futures Trading Commission, which must sign off on the plan, has so far declined to approve it.

Behind the delay is disagreement between ICE and the regulator over how Bakkt—ICE’s name for the project—should be regulated. Bakkt’s initial plan to store customers’ bitcoins ran aground in February, when the CFTC told ICE such a plan would require disclosures of the venture’s business plan and a public comment period, which would have further delayed approval, people familiar with the matter said.

Since then, the regulator and Bakkt have been discussing alternative ways for Bakkt to handle the futures contract so it complies with rules that protect customer funds.

“We are working through the regulatory review process and are looking forward to updating the market soon,” an ICE spokesman said, declining further comment on the regulatory discussions.