Utility-related exchange-traded funds were among the worst performers of Wednesday's market, sinking on the decline in some big names. Exelon ( EXC), PG&E ( PCG) and Centerpoint Energy ( CNP) were all losing close to 2%. The Ultra Utilities ProShares ( UPW) was shedding $2.67, or 3.1%, to $84.23. iShares S&P Global Utilities ( JXI) was declining $1.36 or 2.1%, to $62.87. Utilities HOLDRs ( UTH) was off $2.08, or 1.4%, to $143.45. Vanguard Utilities ETF ( VPU) was losing $1.28, or 1.5%, to $84.52. Funds tracking basic materials also were down. Copper futures were falling 6 cents to $3.39, and mining stocks for companies such as Rio Tinto ( RTP) were declining about 3%. The Ultra Basic Materials ProShares ( UYM) was losing $2.55, or 2.8%, to $89.86. The SPDR S&P Metals & Mining ( XME) was declining $1.33, or 2%, to $65.18. The iShares Dow Jones US Basic Materials ( IYM) was off $1.03, or 1.4%, to $70.32. Bundled securities tracking real estate also suffered, after the National Association of Realtors said it expected home sale prices to fall more than previously expected. The iShares Dow Jones US Home Construction ( ITB) was falling 63 cents, or 1.7%, to $36.05. The Ultra Real Estate ProShares ( URE) was losing 39 cents, or 0.7%, to $59.87. On the flip side, oil and natural gas funds were among the few winners Wednesday. The front-month crude contract was up 34 cents to $65.95, and natural gas futures were up 5 cents to $8.11. Both traded up after news broke that Turkish troops had crossed into northern Iraq in pursuit of Kurdish guerillas. United States Natural Gas ( UNG) was adding 42 cents, or 0.8%, to $52.87. United States Oil ( USO) was tacking on 36 cents, or 0.8%, to $50.38. The iPath Goldman Sachs Crude Oil Index ( OIL) was edging up 28 cents, or 0.7%, to $36.87.