A federal jury yesterday convicted a former businessman of lying about his ties to a terrorist leader, marking the second time Soliman S. Biheiri has been found guilty in a sprawling probe into whether Islamic charities in Northern Virginia were financing terrorist organizations.

Biheiri, 52, was convicted of concealing his business connections to Mousa Abu Marzook, a leader of the Islamic Resistance Movement, or Hamas, who has been designated a terrorist by the U.S. government. The federal jury in Alexandria deliberated for just two hours before reaching its verdict.

Biheiri was indicted in May on the Marzook charge and on separate counts of passport fraud and hiding his dealings with Sami al-Arian, a Florida college professor charged with being a leader of the terrorist group Palestine Islamic Jihad. A judge dismissed the al-Arian count, and Biheiri last week pleaded guilty to illegally possessing and using a U.S. passport to enter the country.

Last year, Biheiri, a native of Egypt, was convicted of lying under oath on his application for U.S. citizenship and was sentenced to one year in prison. Prosecutors are seeking a "terrorism enhancement" to stiffen the sentence for yesterday's conviction, arguing that he obstructed a federal terrorism probe.

If a judge accepts the enhancement at a hearing Oct. 29, prosecutors said, Biheiri could be sentenced to as much as 15 years in prison. If the judge declines, Biheiri probably will receive a year or less in jail and then is likely to be deported to Egypt.

Yesterday's conviction marked another step in the broad terrorism financing investigation. The government alleges that Islamic charities based in Northern Virginia and sponsored by the Saudi Arabian government invested nearly $4 million in BMI Inc., an investment firm that adheres to Islamic principles and was founded by Biheiri in New Jersey in 1986.

At Biheiri's sentencing in January on the earlier immigration conviction, prosecutors said the government believes that Biheiri was dispatched to the United States to start a financial organization as part of a plan to finance and support terror organizations.

The investigation drew widespread attention in March 2002 when federal agents raided companies operating in the 500 block of Grove Street in Herndon and elsewhere in Northern Virginia. The charities have strongly denied any terrorist links.

Prosecutors said during yesterday's closing arguments that the probe is large and complex, with federal agents at times having difficulty penetrating the finances of the Islamic organizations.

In his closing, Assistant U.S. Attorney David Laufman accused Biheiri of lying to federal agents by denying that he had any business ties to Marzook during interviews at Dulles International Airport in June 2003. Laufman said files retrieved from Biheiri's computer showed that Marzook had brought in more than $1 million in investment capital for BMI.

"The defendant showed contempt for the truth,'' Laufman told jurors.

Defense attorney David Schertler focused on the credibility of the agents who interviewed Biheiri, arguing that their handwritten notes did not reflect the alleged lies contained in their official report of the interview. He said Biheiri told the agents that records of his relationship to Marzook had been turned over to the FBI in a separate investigation in Chicago.

Prosecutors and U.S. Immigration and Customs Enforcement officials called the conviction a key step in fighting terrorist financing. "This is an important victory for the government," U.S. Attorney Paul J. McNulty said. Defense attorneys said only that they were disappointed with the verdict.

The probe also led to a guilty plea in July by Abdurahman Alamoudi, a prominent Muslim activist who formerly headed several of the charities under investigation. Alamoudi pleaded guilty to moving cash illegally from Libya and admitted that he was involved in an elaborate Libyan plot to assassinate the de facto Saudi ruler. He is scheduled to be sentenced Friday.