UPDATE 1-US Senate set to consider broader economic sanctions on Iran

WASHINGTON, Nov 29 (Reuters) - The U.S. Senate is set to consider a broader set of economic sanctions on Iran's energy, port, shipping and ship-building sectors, as lawmakers look for new ways to pressure Tehran to stop efforts to enrich uranium to levels that could be used in weapons.

It is the third time in a year that U.S. lawmakers have looked for new ways to cut off revenues they believe fund Iran's nuclear program, which Tehran has said is strictly for civilian purposes.

The new sanctions, which could be voted on as early as Thursday as part of an annual defense policy bill, would also blacklist trade in a list of commodities such as aluminum and steel used in the ship-building and nuclear sectors, according to a copy of the measures reviewed by Reuters.

The sanctions were filed by Senators Robert Menendez, a Democrat, and Mark Kirk, a Republican, who last year co-authored new sanctions that curbed Iran's oil exports and hurt its economy.

Exceptions to the sanctions would continue on oil for importing countries that have made significant cuts to their purchases, the draft bill said.

Natural gas purchases from Iran would be allowed if buyers hold payments in accounts to be drawn on only for permissible trade.

Food, agricultural commodities, medicine, medical devices and humanitarian aid would also be exempt, the draft bill said.