THERE'S BEEN nothing quite like it since Beatlemania. It's Bechtelmania--the concern you hear voiced all over Washington about this giant construction company that seems to be stocking the upper reaches of government the way a fish hatchery stocks the Columbia River. What is the object of this concern? What sort of company is Bechtel?

Secretive, for one thing. Bechtel, based in San Francisco and entirely owned by the Bechtel family and top executives, does not have to, and does not, disclose how much money it makes or how much it pays its 120,000 employees. Successful, for another. Despite the secrecy, there is reason to believe that Bechtel is very profitable and very good at what it sets out to do: build things--big things, like nuclear power plants, new cities in Saudi Arabia, much of Washington's Metro subway system. Bechtel constructed Hoover Dam and the San Francisco-Oakland Bay Bridge, the Transarabian Pipeline and the government buildings of Brunei.

Should Bechtel's business activities give us cause to worry about its alumni and associates in government? The company's extensive dealings with Saudi Arabia and other Arab countries have led some people to doubt whether George Shultz or Caspar Weinberger or W. Kenneth Davis (who is deputy secretary of energy) or Middle East negotiator Philip Habib can be disinterested about American policy in the Middle East. We think their Middle East policies should be assessed on the merits, not on the basis of Bechtel's presumed views. Mr. Shultz and Mr. Weinberger have proved their integrity in some of the most difficult circumstances public officials have ever faced, and Mr. Habib's disinterestedness has the implicit endorsement of the parties whose conflicts he is mediating.

We find it more interesting to ponder the possible effect of the scope of Bechtel's operations on these men's views. Bechtel's work extends around the world. Its main competitors are foreign companies. Its main customers are local and foreign governments and large corporations, not individual consumers. Probably the majority of its business is abroad. We certainly don't think there is material for imputing some sort of conspiracy here, any more than there was when President Carter appointed to high office several alumni of the Trilateral Commission or earlier administrations leaned so heavily on Midwest-based industrial companies for their top businessman appointees--from Charles E. Wilson of General Motors to Robert McNamara of Ford to Neil McElroy of Procter & Gamble.

In our view, anyone who deserves appointment to high office should be able both to use and to transcend the experiences he has had in private life. The good ones do