SANTIAGO, July 18 (Reuters) - Chilean stock indexes traded nearly flat on Wednesday in slow midday trade, as modest gains by electric utilities resisted the negative pull of foreign markets, while the peso slipped against the dollar.

The all-market IGPA stock index .IGPA inched 0.07 percent higher to 14,937 points, while the trade-weighted blue-chip IPSA index .IPSA edged up 0.19 percent to 3,389 points.

"(The power sector) is coming back after days of decline, and that's keeping the trend slightly positive today, but with little volume, little variation and little correlation with foreign markets," a trader said.

Brazilian .BVSP and New York .DJI stock indexes were down 1.18 percent and 0.86 percent respectively in early afternoon trade.

On the Santiago exchange, Endesa Spain regional electric utilities Enersis ENE.SN and Endesa Chile END.SN gained 0.78 percent and 1.1 percent, while generator Colbun COL.SN advanced 3 percent to 114 pesos a share.

Stock in Chile's electricity generators, hit by higher costs amid cuts in shipments of natural gas from Argentina and lower hydroelectric plant reservoir levels, have risen on anticipated increases in wholesale electricity prices.

Industrial conglomerate and wood pulp producer Copec COP.SN, the market's most heavily capitalized stock, offset blue-chips gains as its shares slipped 0.75 percent to 8,159 pesos.

Dominant air carrier LAN LAN.SN saw its stock retreat 1.26 percent to 8,640 pesos a share.

Chilean inflation-adjusted five-year central bank bond yields CLBCU5Y=RR fell to 2.73 percent, compared with the prior session's close at 2.78 percent.

The Chilean peso CHILJ CLP=CL slipped 0.15 percent to 516.30/516.50 per dollar compared with Tuesday's close at 515.50/515.80. (Additional reporting by Manuel Farias)