PORTLAND, Ore. – Radical environmentalist Tre Arrow on Tuesday pleaded guilty to arson charges as part of a deal with prosecutors that will keep him behind bars for more than two years.

Arrow, who legally changed his name from Michael Scarpitti, was charged with firebombing three cement trucks at Ross Island Sand & Gravel in Portland and setting fire to logging trucks and a tractor near Estacada.

On his Web site, the 34-year-old said recently he did not want to risk receiving a life prison sentence and called the plea deal an offer he "couldn't refuse."

On Tuesday, he entered a guilty plea to two counts of arson during a hearing in federal court in Portland.

As part of the deal, he agreed to receive a sentence of 6-1/2 years in prison. However, he will be given credit for the four years he spent behind bars in British Columbia following his arrest in 2004.

The deal also restricts Arrow from associating with so-called eco-terrorist groups, including the Earth Liberation Front and Animal Liberation Front.

His sentencing is scheduled for Aug. 12.

Arrow will serve his time at a medium-security federal prison in Sheridan in Yamhill County.