SAN FRANCISCO (AP) — In the state's latest effort to restart long-stalled executions in California, Gov. Jerry Brown on Thursday ordered prison officials to explore using a single drug for lethal injections instead of three.

Brown's order was disclosed in a two-page appeal of a Marin County judge's decision to toss out California's newly developed lethal injection regulations.

The new procedures called for prisoners to be put to death through the use of sodium thiopental, which may no longer be available in the United States, and two other drugs.

A federal judge in March barred the use of sodium thiopental purchased outside the country. There is no domestic maker of the product, and the California Department of Corrections and Rehabilitation has been ordered to turn over its foreign-bought drug to the Food and Drug Administration.

The FDA is considering whether to appeal the judge's order.

Lawyers for the state Department of Justice said Thursday they would reconsider the appeal if it becomes certain that sodium thiopental can no longer be used in California executions.

Marin County Judge Faye D'Opal in December invalidated the regulations because she said the state failed to explain why it chose the three-drug mixture over the one-drug method, which may have a lower risk of causing undo suffering to the inmate. The judge noted that the state's own expert said the one-drug method was superior.

The appeal says the state still supports the three-drug protocol, but that the governor had directed officials to explore the one-drug option.

"My administration is working to ensure that California's laws on capital punishment are upheld and carried out in conformity with our statutes," Brown said in a prepared statement Thursday.

A federal judge halted executions in 2006 and ordered prison officials to improve their lethal injection procedures or he was going to find California's lethal injection process caused unconstitutional suffering. Since then, the state has constructed a new death chamber at San Quentin Prison, developed new regulations and trained a new team to carry out executions.

U.S. District Judge Richard Seeborg has scheduled a hearing on the federal case Sept. 15, making it clear that no executions will take place in California this year.

But all of the legal maneuvering could be made moot in the fall. A measure to abolish capital punishment in California qualified for the November ballot Monday.