By Keith Chu

WesCom Washington Bureau

WASHINGTON - Oregon Sen. Ron Wyden blocked a presidential nominee Monday to protest the acts of a separate Bush administration official accused of politicizing Endangered Species Act decisions.

The move came as a response to revelations in a federal investigation of Deputy Assistant Interior Secretary Julie MacDonald, released in late March. A federal inspector general found MacDonald, who has no training in biology or natural sciences, helped rewrite reports on endangered species.

The U.S. Fish and Wildlife Service issued a decision in 2004 that the sage grouse didn't need to be listed as endangered.

In a letter to President Bush, Wyden blasted MacDonald's conduct and said he will block Lyle Laverty's nomination to become assistant interior secretary for fish, wildlife and parks until the administration explains how it will prevent such interference in the future.

andquot;Ms. MacDonald has betrayed the mission she swore to uphold,andquot; Wyden said in a written statement. andquot;By placing a hold on Mr. Laverty's nomination, I want the administration to get the message that this behavior must come to a stop for the duration of the Bush administration.andquot;

A hold is a Senate custom that allows individual senators to delay bills or nominations indefinitely. There is no way to overcome a hold.

The White House did not respond to a request for comment. An Interior Department spokesman could not be reached for comment Monday afternoon.

Conservationists praised the move.

andquot;By her actions (MacDonald) has tarnished the whole process,andquot; said Bill Marlett, of the Oregon Natural Desert Association, a Bend, Ore.-based environmental group that backed efforts to list the sage grouse as endangered. andquot;It way beyond any notion of editorial content or scientific accuracy and basically just looking for any little wedge to drive her agenda in.andquot;

The inspector general's report found that she pressured field employees to rewrite reports about the sage grouse and other endangered species and released privileged information to her relatives, friends and attorneys for industry figures.

Wyden spokeswoman Jennifer Hoelzer said the hold does not reflect dissatisfaction with Laverty, but it is a way to demand a response from the administration on MacDonald's conduct.

andquot;He wants to know what the specific steps they are taking to make sure that this sort of thing doesn't happen again,andquot; Hoelzer said.

As assistant secretary for fish, wildlife and parks, Laverty would oversee policy for the U.S. Fish and Wildlife Service and National Park Service, which have a combined annual budget of about $3.6 billion and a combined workforce of about 30,000 employees, according to the Interior Department.

Interior Secretary Dirk Kemp-thorne praised Laverty when he announced the nomination March 26.

andquot;Lyle is an outstanding leader with a lifetime of experience in managing parks and forests and overseeing the stewardship of wildlife,andquot; Kempthorne said in a written statement. andquot;Having served at both the state and federal levels, he sees the complete picture, understands the critical importance of working with communities and is a strong advocate of broad partnership efforts.andquot;

Laverty previously served as head of Colorado State Parks. Kempthorne commended Laverty's efforts to run the parks more as a business and stabilize the agency's finances.

But Scott Silver, of Bend-based conservation group Wild Wilderness, said Laverty sided with industry groups to help privatize state parks.

andquot;Laverty is someone who promoted industrial recreation for many years,andquot; Silver said. andquot;He pushed forward the industry's multipart agenda, which is commercialize, privatize, motorize.andquot;