European stock exchanges closed with gains on Wednesday as traders across the globe prepared for the next monetary policy decision by the United States Federal Reserve, due to be announced at 8 pm CET. Earlier in the day, several Europe-based banks and companies released their latest earnings data, including Credit Suisse, Mercedes-Benz, Deutsche Bank, UniCredit, Lloyds, Rio Tinto and Spotify. Kering and Airbus will reveal their respective results after European markets close for the day.

The DAX closed 0.53% higher with HelloFresh advancing 5.92%. In London, the FTSE 100 increased by 0.57%, pulled up by Smurfit Kappa Group's 5.51% jump. The CAC 40 rose by 0.75% with its best performer Worldline up 13.70% at the close.

The euro was 0.15% higher against the dollar, selling for 1.01315 at 5:29 pm CET, while the pound gained 0.11% compared to the greenback, buying 1.20424 concurrently.