FedEx Corp. (FDX - Get Report) fell in premarket trading on Tuesday, Sept. 18, after it reported mixed financial results for the fiscal first-quarter, even while boosting its full-year profit outlook.

The Memphis, Tenn.-based package delivery company posted net income of $835 million, or $3.10 a share. Adjusted earnings of $3.46 per share missed forecasts calling for $3.80 per share. Revenue of $17.18 billion topped expectations of $16.87 billion.

FedEx raised its full-year earnings per share outlook to a range of $17.20 to $17.80, up from the prior forecast of $17 to $17.60. The company also expects full-year revenue growth of about 9%.

Still, shares of FedEx fell 1.9% to $250.79 during premarket trading. The stock closed on Monday at $255.73, up 0.1%.

The company noted that it "recognized substantially higher variable compensation accruals during the quarter" and "accelerated wage increases for certain hourly employees due to the enactment of the [Tax Cuts and Jobs Act]," which negatively affected year over year results by $170 million. 

FedEx also announced last week that it would expand its U.S. ground operation to six days a week year-round in response to growing e-commerce demand and record influx of volume expected during the holiday season.

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