Jabil Circuit Inc. has mined a lucrative niche that has enabled it to expand in the United States while other electronics manufacturing-services operations have moved overseas.

Jabil's contract manufacturing plant in Tempe, Ariz., specializes in producing printed-circuit boards for about 40 customers, primarily in the medical, aeronautics and defense industries, including defense contactor and airplane builder Boeing Co.

Because the U.S. government heavily regulates those industries, it's not practical to move production overseas, said Gene Sparks, Jabil's director of U.S. sales.

Jabil and other so-called EMS companies make electronic components for original equipment manufacturers, which are increasingly contracting out the work.

Making electronic components is a $250 billion-a-year industry that is growing at more than 10 percent a year. It also is an industry that increasingly has been moving offshore to take advantage of lower production costs.

Instead of shrinking, Jabil's Tempe plant has added about 250 employees in the past two years and continues to expand. The facility, which started with five workers in 1984, now employs 1,100.

Two huge players dominate the industry. Flextronics International Ltd. of Singapore, which after its pending acquisition of Solectron Corp. of Milpitas, Calif., will have annual sales of $28 billion and 160,000 employees, and Hon Hai Precision Industry Corp. of Taiwan with sales of about $30 billion a year and 175,000 employees.