Federal regulators yesterday outlined a new $8 billion plan for bailing out almost 150 insolvent savings and loan associations in the Southwest and nominated a new head for a scandal-plagued agency set up to help solve the nation's savings and loan crisis.

Gerald P. Carmen, who headed the General Services Administration from 1981 to 1985, has been offered the job of president of the Federal Asset Disposition Association (FADA) and is "leaning toward" accepting, said Federal Home Loan Bank Board Chairman M. Danny Wall. Carmen, most recently the U.S. ambassador to the United Nations European mission in Geneva, organized President Reagan's New Hampshire campaign eight years ago and served on the president's transition team before taking the GSA post.

FADA is a "super savings and loan" chartered to help clean up the hundreds of insolvent savings associations and dispose of the billions of dollars worth of foreclosed real estate they own. FADA has been plagued with charges of conflict of interest, favoritism and mismanagement; its first president, Roslyn Payne, was forced out last November, but allowed to temporarily remain a consultant and keep her $250,000-a-year salary, the highest paid any government appointee.

Wall said that if Carmen, who took over GSA after a series of scandals, decides to take the FADA job he will get less than $150,000 a year.

Wall announced the plan to bring in Carmen yesterday in Dallas, where he disclosed the first details of the bank board's long-awaited "Southwest Plan" for dealing with the savings and loans that are losing money in Texas, Louisiana, Mississippi, Arkansas and New Mexico.

The region's 146 insolvent associations -- 104 of them in Texas -- represent "about half of our problems nationwide" and will be the "focal point" of industry reorganization efforts this year, said Wall, who addressed a group of Dallas business leaders and later spoke to the National Association of Homebuilders' annual convention.

Most of the 146 S&Ls that are technically bankrupt but still operating should be reorganized this year, Wall said. He added that the agency will have about $8 billion in cash available for rescue operations, but "prefers to pay the majority of the assistance in the form of a note" or some way other than actually paying off depositors. Estimates of the cost of bailing out all the Texas S&Ls have run to $30 billion or more.

Wall mentioned more than a dozen techniques for refinancing and reorganizing the Texas associations that have lost billions of dollars since the regional real estate market crashed along with oil prices, but he ruled out two specific strategies.

He pledged that the agency will not dump on the market its vast inventory of repossessed real estate -- which would further depress prices -- and will not combine the failed Texas institutions into one statewide savings association.

House Speaker Jim Wright (D-Tex.), who has ties to a number of Texas thrift executives, earlier in the week vowed to fight any effort "to concentrate wealth in fewer and fewer hands" by merging small associations into one big one. Until recently Texas severely restricted branching by financial institutions, and bankers there feared the new competition that would arise if statewide savings associations were allowed.

Wall said yesterday there will be some mergers, but "the bank board does not expect to create any statewide institution." He said the plan calls for creating three kinds of new associations -- community organizations with less than $800 million in assets, regional associations in the $800 million to $2.5 billion range, and bigger multiregionals that would not operate on a statewide basis.

A key goal of regulators, Wall said, will be to bring down the interest rates that Southwest savings associations are being forced to pay to attract depositors. Texas S&Ls are paying as much as 2 percentage points more than those in other parts of the country on savings.