Shares of utility companies were broadly lower Wednesday, with the sector the only one of the S&P 500's /zigman2/quotes/210599714/realtime SPX +0.72% 11 sectors to lose ground, weighed down by a big bounce in Treasury yields. The SPDR Utilities Select Sector ETF /zigman2/quotes/206645117/composite XLU -1.08% shed 1.0% in afternoon trade, with 27 of 28 equity components losing ground. The biggest decliner was NRG Energy Inc.'s stock /zigman2/quotes/208308731/composite NRG -1.01% which slumped 5.1%. Among other more active utilities ETF components, shares of AES Corp. /zigman2/quotes/209256253/composite AES -0.72% lost 2.3%, Excelon Corp. /zigman2/quotes/205982254/composite EXC -1.61% gave up 0.9% and Southern Co. /zigman2/quotes/208000495/composite SO -1.10% shed 0.6%. The lone gainer was Sempra Energy's stock /zigman2/quotes/206074517/composite SRE -0.34% which tacked on 0.6%. Meanwhile, the yield on the 10-year Treasury note rose 3.6 basis points to 2.484%, after falling 10.4 basis points the previous three sessions, as a bounce in the stock market helped calm risk-off trades. Utilities stocks tend to have relatively high dividend yields, so a rise in yields on low-risk Treasurys make them less attractive. The utilities ETF's dividend yield is 3.15%, compared with the implied yield for the S&P 500 /zigman2/quotes/210599714/realtime SPX +0.72% of 1.99%, according to FactSet.