Three telephone company employes in Dallas who had stalked cockroaches in their office building for three weeks split a $1,000 grand prize yesterday in a contest to find the biggest roach in the city and, presumably, in Texas.

The winning entry, an unnamed Periplaneta americana measuring 1.92 inches, was immediately dismissed as inadequate by an exterminator in Houston.

"We know the biggest Texas roach lives in Houston," said John Hartman of Redwood Chemical Inc. He challenged the Dallas roach to a bug-off and has offered $500 and a free trip to Dallas for the biggest roach in Houston.

He's accepting all entries, dead or alive, until July 31.

Just where all this will lead is not yet clear.

Michael Bohdan, coowner of Bizzy Bees Pest Control in Dallas and the David Wolper of roachdom, said he originally wanted the big roach as a star for his local television show "What's Bugging You." Now, however, he says his bug is booked on "The Tonight Show" and has been invited to appear at the Smithsonian's insect zoo.

"This cockroach is going to be famous," he said.

The winner itself was not available for comment. However, its handlers, Marsha McCrackin, 24; Janet Bowman, 33, and Pat Camden, 32 -- all draft clerks with Southwestern Bell in Dallas -- said they captured their entry alive in the office after stunning it with bug spray.

It was selected from among more than 200 entries, which Bohdan said arrived in popcorn boxes, baby food jars, plastic bags and, in one instance, a chauffered limousine.

An early three-inch favorite named Homer, who lived in a peanut butter jar and was being fattened by his owner with sugar water, apparently expired under the rich training regimen. Bohdan disqualified dead cockroaches as insufficiently telegenic.

Meanwhile, in Alabama, a heat wave had sent armies of cockroaches marching on Mobile. Homeowners were getting counsel from urban entomologist Art Appel at Auburn University.

Mobile tends to have the largest roaches in Alabama, Appel said. "Some of the tropical ones from South America can grow to three or four inches."

News of Appel's statement was making its way to Dallas last night.

"This thing has really taken off," said Bohdan. Next year, he says, "we're going national."