However, specialists on ethics say that a partnership arrangement, as described in the documents, raises serious doubts about whether the senator had truly avoided a conflict.
In that case, the HCA stock was accumulated by a family investment partnership started by Frist's late parents. It was later overseen by his brother, Thomas Frist.
Thomas Frist served as president of the partnership's management company and as a top officer of HCA. Senator Frist holds no position with the company.
The senator's share of the partnership was placed in a blind trust between 1998 and 2002 in Tennessee.
It was separate from those governed by Senate ethics rules. Frist reported that Bowling Avenue Partners, made up mostly of nonpublic HCA stock, had brought him $265,495 in dividends and other income over those four years.
Edmond M. Ianni, a former bank executive in Wilmington, Del., who established blind trusts for corporate executives, questioned why the senator's brother was able to manage assets ''when the whole purpose of a blind trust is to ensure lack of not only conflict of interest, but appearance of conflict of interest."
Kathleen Clark, a government ethics specialist at the Washington University School of Law in St. Louis, said she does not think that the Senate trusts or the Tennessee trust insulated Frist from a conflict, because the senator or his brother had been advised of transactions and could influence decisions.
''What I find most appalling is the Senate calls it a qualified blind trust when it's not blind," Clark said. ''Since the Senate says it's OK, the Senate has made it a political question. It's up to the voter. But there's no doubt it's a conflict of interest."
Frist's interest in Bowling Avenue Partners and the blind trust were listed on disclosure reports he filed with the Senate.
The documents said that Thomas Frist was listed as the ''general partner" and ''registered agent" of Bowling Avenue Partners. He also was listed as president of its management company.
Thomas Frist founded HCA, the nation's largest for-profit hospital chain, with his and the senator's father. He currently is the chairman emeritus.
