Gov. Jan Brewer used her veto pen Wednesday to shield Arizona's astronomy industry from the glow of electronic billboards, rejecting a bill that would have legalized the digital boards.

It was her first veto of the year and underscored her commitment to what she called "Arizona's unique position as a national leader in astronomy and stargazing."

House Bill 2757 would have brought 70 electronic billboards into compliance with the state's Highway Beautification Act. A state appeals court last year ruled the boards, with their constantly changing messages, violated the state's ban on intermittent light.

The astronomy industry, led by representatives of the state's largest observatories, argued the bill could ruin the dark skies that have made Arizona a prime site for astronomical research.

Jeff Hall, director of the Lowell Observatory in Flagstaff, said Brewer's veto will prevent, at least for now, a proliferation of electronic billboards. More importantly, he said, it's an important economic signal.

"It sends a message from the executive office that Arizona is committed to the industry and the potential $300 million investment it brings," he said.

Arizona is competing with five countries for the $130 million Cherenkov Telescope Array near Flagstaff. An additional $170 million is tied up in three other projects coming to Arizona, Hall said.

In her veto letter, Brewer offered hope to billboard representatives, saying she has won assurances from Rep. Bob Robson, R-Chandler and the bill's sponsor, to work on a compromise.

Robson late Wednesday said he was unclear what would be workable.

"I don't know how much work can be done if the observatories want a 75-mile radius," he said, referring to their demand for a buffer zone around telescope sites.

"I'm scratching my head as to what to do. ... It comes down to people not really wanting to have (electronic) billboards."

But Wendy Briggs, who represents Clear Channel Communications, which owns some of the 70 billboards in question, said her client will take Brewer up on her offer to compromise.