Craig Donohue’s turnaround plan for the nation’s options clearinghouse has hit a roadblock.

Mr. Donohue has boosted the prominence of Options Clearing Corp., which acts as a guarantor for every trade in the U.S. listed options market. Clearinghouses—critical parts of the financial system—came under greater scrutiny after the last financial crisis and are responsible for preventing potential defaults from rippling through markets.

But after four years at the helm, the OCC’s executive chairman and chief is locked in a fierce battle with options traders who oppose his plan to boost income for OCC shareholders—three publicly listed exchange-operators—while trimming returns to traders.

A group of trading firms and smaller, competing exchanges, including Susquehanna International Group LLP and Virtu Financial Inc., made the unusual move of suing the Securities and Exchange Commission in 2016 for approving the OCC proposal early that year, throwing the plan’s fate up in the air. The SEC is currently re-reviewing it on the order of a U.S. appeals court. A spokesman for the SEC declined to comment.

Though the plan remains in place and has been paying dividends to shareholders, its future is unknown. Shareholder payouts have been climbing since their inception in 2015, hitting a high in 2017, according to OCC financial statements and comments to the SEC.