Promising to stick to the same philosophy he has voiced in Congress for the past five years, Rep. Howard Nielson, R-Utah, announced Monday his bid for a fourth two-year term from Utah's 3rd congressional district.

Nielson is the only congressman the district has had since it was formed in 1982, and he has never faced a serious challenge from a Democratic opponent. But he promised not to let that history affect his campaign strategy."I believe nothing is a sure thing," the Richfield native told a crowd of supporters at the State Capitol. "I'm going to do what I've always done run as if it's the toughest race in the world."

Although Nielson defeated Riverton mayor Dale Gardner, his 1986 Democratic challenger, by a 2-1 margin, the congressman noted his standing with 3rd District voters in that election slipped about 10 percentage points from his 1984 victory margin.

The former Brigham Young University statistics professor said he won't lose any more ground among voters in 1988 and pledged to hold his campaign spending to $100,000 as he has in his previous 3rd District races. His campaign committee already has about $55,000 bankrolled.

Two Democrats Craig Oliver, who challenged Sen. Jake Garn two years ago, and Utah County Democratic Party chairman Bob Stringham have indicated interest in challenging for the 3rd District seat. Nielson said he doesn't care which opponent he will face in November.

The congressman also said he is unaware of any potential Republican candidates who might challenge him in a primary race.

`I don't expect a challenge from within the party, but recent events show you can't always tell about those things," he said in reference to the decision of industrialist Jon Huntsman to challenge Gov. Norm Bangerter for the Republican gubernatorial nomination. "Sometimes they come out of the blue."

Nielson said his assignments to House committees Energy and Commerce, and Government Operations give him an excellent position to represent

his district. Through those assignments he is involved in energy, steel, copper, trade, tourism, telecommunications and environmental issues.

"I will continue my work to make clean air legislation fair to the West," Nielson said. "We need to take care of our problems in that area because we don't want the acid rain the East has. But I believe the polluters should pay for cleanup and should be able to use the most cost-effective method."

He cited his work for tax incentives benefiting Geneva Steel and Kennecott, his efforts to ensure rural health care facilities of their share of federal funding and his introduction of a bill that would help bring cable television to rural communities outside the range of TV signals.

Nielson's wife, Julie, and his daughter, Jean Kundick, will manage his campaign. The pair also managed Nielson's successful 1986 re-election bid.