European shares are ending the day mixed in relatively quiet trading, with the U.S. markets closed for the Labor Day holiday.Higher oil prices provided support for energy shares, but there is another side to that story. Rising energy costs can keep inflation elevated and increase the pressure on central banks to raise interest rates. That concern helped push European yields higher and limited the enthusiasm in the broader equity markets.The major indices are closing:Germany’s DAX: -0.15% at 26,006.53France’s CAC 40: +0.33% at 8,306.15U.K.’s FTSE 100: -0.08% at 10,822.13Spain’s Ibex: -0.14% at 20,021.80Italy’s FTSE MIB: +0.25% at 52,230The pan-European Stoxx 600 finished near unchanged at 649.90.Energy shares were among the better performers as Brent crude moved closer to $100 per barrel. European technology shares also received a boost from the strong rally in Asian semiconductor stocks. On the downside, healthcare shares were pressured by a 3.2% decline in Novartis after disappointing drug-trial results.Germany’s DAX lagged modestly amid political uncertainty following the AfD’s election victory in Saxony-Anhalt. France’s CAC 40 moved higher after recently coming under pressure from concerns about the country’s fiscal outlook.In the European debt market, benchmark 10-year yields moved higher:Germany: 3.39%, +4.9 basis pointsFrance: 4.25%, +4.0 basis pointsU.K.: 5.18%, +4.0 basis pointsSpain: 3.83%, +5.5 basis pointsItaly: 4.22%, +7.0 basis pointsRemember that bond prices and yields move in opposite directions. As a result, the move higher in yields represents selling in the European debt market.The catalyst is the renewed concern that rising energy prices will keep inflation elevated and force central banks to maintain tighter monetary policy. The ECB is widely expected to raise rates by 25 basis points on Thursday. Deutsche Bank is also forecasting another 25-basis-point increase in December.For stock traders, the rise in oil creates a push and pull. Higher crude prices are supportive for energy companies, but they also raise costs throughout the economy and can keep interest rates higher. Higher yields can then weigh on equity valuations—especially for growth companies whose expected earnings are further into the future. This article was written by Greg Michalowski at investinglive.com.