WASHINGTON — Federal prosecutors plan to move an alleged al-Qaida sleeper agent out of a Navy brig in South Carolina and send him to federal court in Illinois to face trial.

Two people familiar with the case of Qatar native Ali al-Marri said today the government plans to transfer him to the civilian court system. The two people spoke on condition of anonymity because no official announcement has been made.

The transfer could avert a Supreme Court hearing in April and a subsequent ruling that would govern other cases against accused terrorists. To justify holding al-Marri, the Bush administration claimed the president has the wartime authority to send the military into any U.S. neighborhood, capture a citizen and hold him in prison without charge, indefinitely.

One of the people familiar with the al-Marri case said prosecutors plan to charge al-Marri with providing material support to terrorists, a charge similar to what he would have faced if tried by a military tribunal.