ExxonMobil wants to build a $1 billion liquefied natural gas terminal 20 miles off the Jersey Shore, a project designed to deliver new supplies of the fuel to a region where rising demand and tight supplies have led to steady price increases for consumers. The project, which would require approval of the U.S. Maritime Administration and Coast Guard, joins three other proposals to build LNG terminals in New Jersey and other parts of the metropolitan area to avert expected shortages of natural gas supplies over the next decade. Natural gas is viewed by energy companies as a cleaner and potentially cheaper option for generating electricity if state and federal governments impose, as expected, tough new curbs on greenhouse gas emissions. Senior executives at Exxon touted the project, dubbed BlueOcean Energy, saying the floating terminal will have the capacity to supply about 1.2 billion cubic feet of natural gas per day, enough to meet the needs of more than 5 million residential consumers. "We believe that BlueOcean Energy is a unique and innovative solution to meeting the region's energy needs,'' said Ron Billings, a vice president of the Irving, Tex., energy conglomerate. There is only one offshore LNG terminal currently in the U.S., located in the Gulf of Mexico off Louisiana, but a number of other proposals have been developed to build offshore terminals, largely because of the fears of siting the facility in populated areas because of the highly combustible nature of liquiefied natural gas. There are four onshore LNG terminals, including near ports in Boston and another in Baltimore. The project likely faces opposition from conservationists and fishing groups, who have banded together to denounce another offshore natural gas terminal proposed 19 miles east of Sandy Hook. Atlantic Sea Island Group is proposing to build a 63-acre artificial island where the LNG would be heated and converted to gas and sent through a pipeline to the New Jersey coast. Beyond that plan, there is a proposal pending to build a LNG terminal in Logan Township on the Delaware River, and another plan to construct a floating terminal in Long Island Sound, about nine miles off the Long Island coast.