WASHINGTON - Texas Sens. Lloyd Bentsen and Phil Gramm helped defeat a measure that would have cut funding to upgrade a battleship that is to be placed in service at a Gulf Coast port by 1990.

The Reagan administration is to decide by July 4 which of six Gulf ports the USS Wisconsin will call home. Consequently, the measure, an amendment to a Department of Defense authorization bill triggered opposition from every senator representing a Gulf Coast state except one from Mississippi.

Sen. J. James Exon, D-Neb., the principal co-author of the amendment, contended that about $54 million earmarked for renovating the USS Wisconsin during the government's fiscal year beginning Oct. 1 could be better spent on Naval munitions. He also argued that a fourth battleship in the U.S. fleet was unnecessary.

But with about 3 ,700 jobs, an annual payroll of about $50 million and $100 million in construction work to be won, and Houston-Galveston and Corpus Christi among the finalists, Gramm and Bentsen gladly took turns debating Exon and two of his three co-sponsors Sens. Dale Bumpers, D-Ark. and John Chafee, D-R.I.

Gramm, a freshman Republican, argued that reviving the USS Wisconsin meant U.S. naval firepower and mobility would not be diluted. He said recent improvements by the Soviet navy required a proposed $53.5 million expenditure on the USS Wisconsin to be made on schedule.

Not to be outdone, Bentsen, a Democrat, said the upgrading represents the best taxpayer value for the dollar.

"Since he is a former admiral in the Nebraska Navy and one who understands the flats sometimes look like the Sahara," said Bentsen, speaking of Exon and Nebraska, "I can understand my friend from Nebraska not being enthusiastic about naval seapower."

Exon, recognizing that, "The South has risen today," said he did not expect the amendment to succeed. The move was defeated 30-68.

The total cost to upgrade the USS Wisconsin is projected to be $476 million. The four other cities competing for the right to base the USS Wisconsin are Mobile, Ala.; Lake Charles, La.; Pensacola, Fla.; and Pascagoula, Miss.

With the USS Wisconsin based on the Gulf Coast, the Navy would have one ship on each coast with a fourth, designated as a spare, in Hawaii or Northern California.

Meanwhile, negotiations on the MX missile broke off Wednesday night and backers of a limit on missile deployment prepared for a long night of debate on the Senate floor.

The Senate turned aside from the MX missile briefly to take up the question of chemical weapons. A vote was expected later on a proposal to trim $163 million earmarked for renewed nerve gas production from the $302 billion fiscal 1986 defense authorization bill.

In other congressional action compiled from wire reports:

Industry controls Three House members, citing the Bhopal disaster and charging inaction by the Reagan administration, introduced legislation to slap broad federal controls on the vast U.S. chemical industry. "As far as we can determine, there are millions of pounds of known and suspected carcinogens (cancer-causing substances) that are emitted into the air annually with no restrictions," said Rep. James Florio, D-N.J. A co-sponsor, Rep. Henry Waxman, D-Calif., said, "This comprehensive bill can help prevent future tragedies like Bhopal and reduce the incidence of cancer and other life-threatening diseases."

Teen wages Secretary of Labor William Brock urged Congress to allow teen-agers who take summer jobs to be paid a below-minimum wage, or risk producing a generation of young people who will be dependent on welfare. "Teen-agers who cannot gain the work experience in the first place are often destined to drift into a netherworld of lifelong unemployment, welfare and crime from which they will not escape," Brock told the Senate Committee on Labor and Human Resources. The department estimates a subminimum wage would create 400,000 jobs for young people.