A Texas entrepreneur who spent $ 2.5 million on ads backing George W. Bush for president said Tuesday he's getting out of political advertising.

Sam Wyly, who with his brother has donated more than $ 210,000 to Bush, stirred the presidential campaign last month with the Republicans for Clean Air ads. Broadcast in New York state, Ohio and California, the ads praised Bush's environmental record and attacked rival John McCain.

In a speech Tuesday in Seattle, Wyly said the ads were not effective in publicizing his message about environmentally friendly power and that he would not be making any more.

"Many of you are aware of my recent foray into presidential politics. I have already decided it is to be my last," he said upon receiving an award from the Climate Institute. "I thought I had a clever idea to get America to focus on the clean air issue and to help my presidential candidate."

Wyly burst onto the scene just days before the Super Tuesday primaries March 7, when Bush clinched the nomination, and said he planned to air other ads during the fall campaign.

He was a controversial figure from the start, declining to identify himself as the man behind the ads until they had run for a day.

Wyly said he regretted that hundreds of media reports about his effort "did not carry the message that I had hoped to get out," on the importance of allowing competition in the electric utility field and of forcing old coal-burning power plants to clean up their emissions.

Both goals would benefit his company, GreenMountain.com, which sells renewable energy in states that allow competition.

Wyly, who has donated money to Bush family campaigns and other Republicans for decades, plans to remain politically active - just not as an ad maker, said Thomas Rawls of GreenMountain.com.

The Republicans for Clean Air ads were widely denounced by environmental groups. In his speech, Wyly indicated he was uncomfortable being on outs with those organizations.

"I know from time to time many of us may disagree on our politics, our candidates and our methods, but what I do know is that everyone in this room is committed to cleaner air through cleaner energy," he said.