After several days' search for potential candidates to serve as chairman of the Republican Party, the White House list continues to "expand and contract" and now includes Agriculture Secretary Clayton Yeutter, officials said yesterday.

White House Chief of Staff John H. Sununu said it is "not a closed list. Names are being added and subtracted externally and internally." He said Yeutter is "on the list" and called him "a strong possibility. He's a good man."

But it was unclear yesterday whether Yeutter, 61, will go the way of William J. Bennett, the former director of drug control policy who changed his mind about accepting the post after his hopes of earning a substantial outside income were questioned by the White House legal counsel and other lawyers. Yeutter, who would not comment, has been said for months to be interested in leaving the administration for the private sector, but friends of his said yesterday that earning potential would not be a major problem.

Yeutter, who served as special trade representative in the Reagan administration and as agriculture secretary since President Bush took office, has no known significant political experience and, unlike Bennett, is not a proponent of any particular ideology, but he has been an articulate and sometimes combative advocate of administration farm and trade policy.

Sununu said Yeutter has "strong experience in grass-roots politics," but his biography lists only one post with political overtones: executive assistant to the governor of Nebraska two decades ago.

Yeutter, who has a doctorate in agriculture and a law degree, had been involved in farming 2,500 acres and raising cattle in central Nebraska and in teaching before coming to Washington as an assistant secretary in the Agriculture Department in the mid-1970s. He was president of the Chicago Mercantile Exchange from 1978 to 1985, when he was named special trade representative by former President Ronald Reagan.

The White House has had difficulty filling the Republican chairmanship, now held by the ailing Lee Atwater. Many of those who have been approached had lucrative businesses that they were unwilling to give up for a position that is significantly diminished in a presidential election cycle, when Bush's reelection team and White House political team will call most of the policy shots.

It was unclear yesterday whether Sununu was contacting potential candidates at Bush's specific behest or compiling a list from which Bush would make a final choice. One party source said the president had been unsure from the outset whether he wanted a skilled political technician or a type of national spokesman for the post, as Bush himself had been when he served as Republican National Committee chairman in 1974.

Rich Bond, a former deputy chairman of the party and political director of Bush's 1988 campaign, was considered the leading candidate in the party-operative category because of his strong ties to the White House, Bush partisans and GOP officials nationwide. But Sununu said Bond had informed the White House he was withdrawing his name from consideration for business and family reasons.

Officials said yesterday Bush will have to decide soon because the candidate will need at least two weeks to meet with national committee members and assess party operations before the RNC meets Jan. 25 to vote on a new chairman.