WASHINGTON, D.C. — Charges that a detained leader of the militant fundamentalist Hamas movement ran a terrorist network from the United States has renewed the Jewish call for Congress to pass tougher anti-terrorism legislation.

But prospects that the bill now under consideration would thwart people such as Musa Muhammad Abu Marzook from engaging in extensive U.S. fund-raising do not appear encouraging.

Marzook, 44, was arrested July 25 at New York's Kennedy Airport after stepping off a plane from Dubai, a city and sheikdom of the United Arab Emirates.

Israel has officially launched proceedings to extradite Marzook, who has lived in the United States for 19 years.

In a brief New York court hearing Tuesday of last week, a federal magistrate formally told Marzook of Israel's desire to extradite him on charges of terrorism and conspiracy to commit murder.

According to an Israeli complaint presented to the court, Marzook heads the political bureau of Hamas, which rejects the Israeli-Palestinian peace process.

But the complaint also called Hamas' political bureau responsible for "directing and coordinating" the group's terrorist acts in Israel and the territories. The complaint blames Hamas for killing 70 Israeli civilians and 40 soldiers and wounding nearly 100 others since January 1989.

Marzook has admitted that he is a political leader and fund-raiser for Hamas, but has denied taking any part in violence.

Marzook's lawyer, Stanley Cohen, reportedly said it would be difficult for Israel to prove its case in a United States court.

The Israeli complaint also said Marzook transferred hundreds of thousands of dollars to the Gaza-based Hamas.

U.S. law enforcement officials estimate that Hamas has raised tens of millions of dollars in this country.

Fund-raising among terrorist organizations has been a central concern for Jewish groups advocating tough anti-terrorism legislation.

Congressional calls for anti-terrorism legislation increased after April's Oklahoma City bomb fiasco. At that time, the debate's emphasis shifted from international terrorism to domestic terrorism.

In June, the Senate passed a bill seeking to combat both domestic and international terrorism by allowing broader government investigations, tighter immigration controls and bans on terrorist-organization fund-raising in the United States. The bill allows the State Department to designate a group as terrorist and thereby render illegal any donations made to the group.

But Jewish groups were quick to attack those provisions related to fund-raising, charging that the measure was riddled with loopholes.

Critics protested that the bill excludes a ban on the group's domestic affiliates, and requires the government to prove before a judge that the targeted organization's governing body knowingly supported terrorist activity. The bill requires a 30-day waiting period before the ban on a designated terrorist group can take effect.

Making counterterrorism legislation a centerpiece of their Washington agenda, Jewish groups now pin their hopes on the House of Representatives to rectify the Senate bill's problems.

The House Judiciary Committee passed a bill earlier this summer, and floor debate in the House is scheduled for late September or early October.

Most Jewish activists publicly support the House version of the bill.

"Our feeling is that the House bill goes a long way in dealing with terrorism," said Jess Hordes, Washington director of the Anti-Defamation League.

But privately, some say that even though the bill does revise some of the provisions related to fund-raising, it would not prevent fund-raising by terrorists.

Although it eliminates the 30-day "stay" period cited in the Senate bill, the House bill would allow for a period of "public comment," which many believe could still leave enough time for groups to transfer funds before being shut down.

Further, the House version does not exempt domestic conduits from receiving money as the Senate bill does, but neither does it explicitly bar them. And, unlike the Senate version, the House bill does not freeze terrorist assets in American financial institutions.

Most Jewish groups believe the House bill would be more effective in countering terrorist activities in this country.

At the same, they worry that it would not do enough to contain the U.S.-based activities of Marzook and his Hamas organization, whose network is believed to be growing.

Marzook's detention by immigration officials when he tried to enter the United States last month has renewed a call for tougher law enforcement against immigrants suspected of terrorism. Such provisions are being considered as part of the terrorism legislation.

But raising the specter of immigration restrictions also raises thorny civil rights questions.

Jewish groups disagree over how best to maintain civil liberties while at the same time enabling the deportation of immigrants suspected of terrorism. Despite all the jostling over details, however, Jewish leaders say the legislation's overall importance must be kept in perspective.

"The very fact that we have a bill for the first time that will address terrorism is a very important step," said Malcolm Hoenlein, executive vice chairman of the Conference of Presidents of Major American Jewish Organizations.

"One or two years ago, people thought it wasn't possible."