JetBlue Airways is planning a host of new cost-control measures including reducing flights and parking some of its jets, as weak demand for travel hurts margins, according to an internal memo seen by Reuters.

The shares of the carrier fell nearly 5% in premarket trading.

The airline is also assessing the size and scope of its leadership team and has identified ways to combine or restructure some roles, JetBlue CEO Joanna Geraghty said in the memo to employees.

The company declined to comment.

The cost-control measures were first reported by CNBC.