Two members of Dallas-based Tenet Healthcare’s board of directors abruptly resigned Thursday citing “irreconcilable differences” with the national hospital operator.

Randy Simpson and Matt Ripperger are both representatives with Tenet's largest shareholder, New York-based hedge fund Glenview Capital Management. After 19 months on the board, they quit this week stating in a joint letter that they disagree with Tenet on "significant matters."

Both Glenview Capital Management and Tenet declined to comment.

But the departures notably come about a week after Tenet reported a higher-than-expected second-quarter loss and slashed its forecast on annual revenue.

While performance was disappointing, it was not disastrous nor out of line with current trends, said one health care analyst, who called the resignations "a surprise."

“It makes me wonder what the boardroom discussions have been like the past few weeks,” said Sheryl Skolnick of Mizuho Securities. “It’s rare that shareholders go on the board to begin with. And it’s even more rare that they have these kinds of public disagreements and resign,” she said.

The board of directors is a group of elected individuals representing a company’s stockholders. They help to establish management policies and make decisions on major issues.

Teamsters, a union with more than 1.4 million members, criticized Tenet's board this spring for approving a multi-million dollar executive payment plan despite continuing losses, a falling stock price and a half-billion dollar legal settlement, all of which impacts shareholders.

The group said Friday that it is monitoring the recent board change, but declined to comment further.

Tenet's board now consists of its chief executive officer, Trevor Fetter, as well as 11 independent directors. Those include Tammy Romo, the executive vice president and chief financial officer for Dallas-based Southwest Airlines, and Ronald Rittenmeyer, chairman and chief executive officer of California-based Millennium Health.

Glenview owned nearly 18 percent of Tenet's shares and had been a substantial investor before its two representatives joined the board in January 2016. Glenview's shares were worth around $225 million when the stock market closed Thursday, according to a Reuters report.

The presence of Simpson and Ripperger limited the type of activities Glenview could perform, like buying and selling stock or engaging in a proxy fight. In order to take on those actions, the two nominees would have to step down.

The New York hedge fund can now do so following a 15 day wait, due to a “restrictive standstill" agreement. “After which Glenview may evaluate other avenues to be a constructive owner of Tenet,” the letter said.

Tenet’s stock prices were up more than 13 percent midday Friday trading at $14.28 a share.

Shares were trading at nearly $30 per share this time last year, and at $16 per share earlier this month before it released second quarter financials. Tenet attributed the miss in second quarter to a decline in patient volume and higher rates of uncompensated care, among other factors.

It also lowered its full-year financial outlook. Previously the company predicted annual revenues would reach between $19.7 and $20.1 billion. That estimate was lowered to a range between $19.1 billion and $19.4 billion.