The wealthy Pritzker family of Chicago offered more than $85 million yesterday to buy up all the stock it doesn't already own in two hotels chains, Hyatt Corp. and Hyatt International Corp.

Hyatt Corp. has been under investigation for more than a year by the Securities and Exchange Commission. Among the areas being looked at are lease agreements that, in effect, shift the risk of owning hotels from the Pritzker family to the corporation. The SEC raised the question whether there was adequate disclosure of any conflicts of interest between the Pritzkers as landlords and as tenants, ants.

The family owns all or part of several hotel leased and operated by the Hyatt companies.

A spokesman for the family, attorney Allen M. Turner, said yesterday that one of the "many business reasons" for the decision to return the companies to privately held concerns is the ongoing SEC investigation.

"Certainly there is a desire to eliminate any questions of conflicts." He repeated the family contention that no wrongs have been committed. Turner said the SEC hasn't "told us specially what they are investigating, nor is there any evidence that they have found anything."

The family now owns 1.2 million shares, or about 55 percent of the total outstanding of Hyatt International, and is offering $9 a share for the rest, whose value over-the-counter yesterday was just above $8. The company operates or manages more than 20 hotels outside the United States.