Tennessee is watching Saturn plant speculators.

The state’s real estate commission sent two investigators to Spring Hill, Tenn., to monitor brokers and out-of-town investors hoping to capitalize on General Motors’ planned $3.5-billion auto project. State and local officials are warning against unscrupulous buyers and sellers of property, saying that they’re seeing some misleading sale contracts that are unfair to sellers and other cases of swampland being offered at vastly inflated prices. No charges have been filed, however, according to the real estate panel.