U.S. stocks traded slightly lower Wednesday as investors awaited minutes from the U.S. Federal Reserve’s latest meeting. Wednesday’s declines were led by losses in airline stocks, with shares of Southwest Airlines Co. dropping more than 8 percent.

In midday trading, the Dow Jones Industrial Average (INDEXDJX:.DJI) fell 12.88 points, or 0.07 percent, to 18,300. The Standard & Poor's 500 (INDEXNASDAQ:.IXIC) lost 1.53 points, or 0.07 percent, to 2,126. The Nasdaq composite (INDEXSP:.INX) dipped 1 point, or 0.02 percent, to 5,069.

Minutes from the Federal Reserve’s April meeting will be released Wednesday at 2 p.m. EDT.  Economists will look for hints as to when the central bank plans to raise interest rates. The Fed kept interest rates at historic lows following its two-day policy meeting on April 28-29, and most economists anticipate the central bank will lift rates as early as September after the U.S. economy grew slower than expected in the first quarter.

"We don't expect any new indications coming from the minutes that would gauge the future course of action of Fed policy," said Terry Sandven, chief equity strategist at U.S. Bank Wealth Management. "We could perhaps glean some insight into the Fed's assessment of how a stabilization in the U.S. dollar and oil prices are affecting the overall economy, and specifically, the likelihood of a September liftoff."

The biggest laggards in the Dow Wednesday were banking giant JPMorgan Chase & Co. (NYSE:JPM) and McDonald's Corporation (NYSE:MCD), both down 0.8 percent.

Chipmaker Intel Corporation (NASDAQ:INTC) and Caterpillar Inc. (NYSE:CAT), the world’s largest manufacturer of construction and mining equipment, were the largest gainers in the Dow Wednesday, gaining 0.7 percent and 0.6 percent, respectively.

The Dow Jones Transportation Average dropped 1.5 percent as airline stocks tumbled.

Shares of Southwest Airlines Co. (NYSE:LUV) dropped more than 8 percent after the company announced it expects passenger revenue per available seat mile, which measures sales relative to a planes' capacity, to fall 3 percent in the second quarter from a year earlier.  

Meanwhile, American Airlines Group Inc. (NASDAQ:AAL) shares dropped 6 percent to as low as $43.68, falling below the stock’s 200-day moving average.

Shares of Etsy Inc. (NASDAQ:ETSY) plunged 23 percent Wednesday, a day after the online crafts marketplace posted a wider-than-expected loss in the most recent quarter. 

Target Corporation (NYSE:TGT) edged higher Wednesday after the second-largest U.S. discount retailer posted a 52 percent jump in earnings, driven by a boost in online sales. 

Notable companies reporting earnings after the closing bell Wednesday include cloud computing company Salesforce.com, Inc. and retailer L Brands Inc.