Update (May 20, 12:32 p.m.): In the letter, released on Tuesday by attorney Allan Van Fleet, Hall crticized Chairman Paul Foster's handling of the House Select Committee on Transparency in State Agency Operations investigation and the decision to ask for his resignation.

"The result is that you have used your position to participate in a campaign that is intended to impugn my reputation," Hall said.  "You have also allowed a small group of legislators to interfere in the Board's official opperations."

Citing letters sent to the transparency committee by System outside counsel Phillip Hilder and Chancellor Francisco Cigarroa in early 2014, Hall said the committee has found no evidence of wrongdoing on his part. A report released in April by Rusty Hardin, special counsel to the transparency committee, determine Hall had likely committed impeachable offenses.

After Tuesday's UT System Board of Regents meeting, Foster said he read the letter and will not pursue the issue any further.

"I pledge to work closely with him, as I have in the past," Foster said. "As far as I'm concerned, that's history."

Original story (May 19): UT System Regent Wallace Hall said he will not resign in a letter to Paul Foster, Board of Regents chairman, according to Hall’s attorney Allan Van Fleet.

Foster publicly asked Hall to resign at a regents meeting on Thursday. A few days before on May 12, the House Select Committee on Transparency in State Agency Operations determined grounds for Hall’s impeachment exist in a 7-1 vote. The committee is scheduled to meet on Wednesday and Thursday to develop specific articles of impeachment.

In a statement, Hall said he has been working to point out wrongdoing at System's institutions.

"Will the public ever know the truth about problems in our institutions if legislators are allowed to impeach Board members who reveal them?" Hall said.

The committee began investigating Hall in June 2013 after state legislators accused him of overstepping his authority as a regent and seeking the removal of President William Powers Jr. from his position.

According to System spokeswoman Jenny LaCoste-Caputo, Foster has not yet received the letter. The regents are schedule to meet via teleconference on Tuesday.