WASHINGTON, D.C. — The United States has moved one step closer to imposing broad economic sanctions against foreign firms that invest in Iran and Libya.

In a voice vote Tuesday night, the Senate approved a measure that would impose sanctions on overseas businesses that contract with Libya's and Iran's lucrative energy industries or assist the outcast states in building up their chemical or nuclear weapons programs.

The House of Representatives unanimously passed a similar measure last month.

House and Senate negotiators will now meet to hammer out differences in each version of the bill.

The Senate opted to include tougher sanctions against Libya. President Clinton is known to favor the House version and has said that he will sign a compromise bill.

"The bill sends a message that the United States is not willing to stand by as rogue regimes threaten U.S. interests and those of its allies," said an American Israel Public Affairs Committee official.

The bill would force foreign firms to choose between doing business with Iran and Libya or the United States.

Under the threat of the legislation, at least four European companies have backed away from planned deals with Iran worth more than a total of $10 billion.

By cutting off money to Iran's energy industry, supporters of the bill hope that the cash squeeze will curtail the militant Islamic regime's support for terrorism.

Both the House and Senate versions require the president to impose at least two of six possible sanctions on a company that violates U.N. embargoes or that invests more than $40 million in developing oil and gas resources, chemical weapons or nuclear weapons.

The leveling of such sanctions would amount to a de facto boycott.

The sanctions include denying the firm U.S. government loans and credits, banning the company from bidding for U.S. government contracts, preventing the firm from receiving export licenses to ship goods to the United States and blocking loans from U.S. banks.

In addition, financial institutions could lose eligibility to receive U.S. government deposits and trade in debt instruments, including U.S. government bonds.

The president could waive the sanctions if he determines that it is in the national interest of the United States or if the company is subject to punishment by its home country.