* "Meaningful steps" sought towards human rights
* Relatively rare for lawmakers to oppose such sales
WASHINGTON, Oct 14 (Reuters) - The United States held out the possibility on Friday it may not sell $53 million in arms to Bahrain, saying it had not made a final decision to transfer the materiel and human rights would weigh in its assessment.
The Pentagon on Sept. 14 notified Congress of its intent to sell more than 44 armored Humvees and 300 TOW missiles to Bahrain, whose crackdown on a popular uprising this year has prompted some U.S. lawmakers to oppose the sale.
"This is a notification about future intent," U.S. State Department spokeswoman Victoria Nuland told reporters. "We will continue to take human rights into consideration as we make future decisions about this."
Senator Ron Wyden and Representative James McGovern, both Democrats, have introduced resolutions in Congress to prevent the sale "until meaningful steps are taken to improve human rights" there.
As the so-called "Arab spring" swept authoritarian governments from power in Egypt, Tunisia and Libya, Bahrain's Shi'ite majority turned up the political heat in the island country.
The Sunni ruling family in the Gulf Arab state has put down the pro-democracy uprising with the help of neighboring Saudi Arabia and of the United Arab Emirates.
Many Shi'ite areas are witnessing almost nightly clashes with police. Opposition groups say heavy-handed police tactics are worsening tension on the street.
About 30 people, mainly Shi'ites, died when the protest movement erupted in February, but ongoing clashes and deaths in police custody have taken the total past 40, according to the Bahrain Center for Human Rights.
"Proceeding with the announced arms sale to Bahrain without modification under the current circumstances weakens U.S. credibility at a critical time of political transition in the Middle East," Republican Senator Marco Rubio wrote Secretary off State Hillary Clinton in a letter on Thursday.
It is relatively rare for U.S. lawmakers to oppose such arms sales because they are typically vetted with Congress before they become public.
Prime contractors for the arms sale would be AM GeneralRaytheon Co , according to the Defense Security Cooperation Agency, the part of the Pentagon that oversees foreign arms sales.