LifePoint Hospitals Inc. said Thursday it plans to buy back up to $150 million of its common stock over the next 18 months.

The company has already repurchased about $45 million in stock under a prior buyback plan that will continue through February.

The company has about 54.2 million shares of common stock outstanding.

Meanwhile, shares of LifePoint fell $1.67, or 4.5 percent, to $35.02 in midday trading. The stock has traded between $25.78 and $39.61 over the last 52 weeks.

The company canceled several investor meetings this week and shares have swung wildly over the last two days.

Raymond James analyst John W. Ransom said the stock buyback plan reflects management's "increasing confidence in company operations and more aggressive capital deployment." But, said the stock decline Thursday was expected given a sharp jump on Wednesday over speculation from the canceled meetings.

He reaffirmed a "Market Perform" rating.