SAO PAULO, Dec 11 (Reuters) - Mills in Brazil's main cane producing region extended operations into December as rain reduced harvest pace and also sugar content in cane, industry group Unica said on Tuesday. Unica said that 132 mills were still operating in December, a period when normally the season is basically over, since widespread rains over most of the center-south region lead to pauses in field work. At the end of November last year, 150 mills already ended operations compared with 131 mills this year. Center-south sugar production reached 528,000 tonnes in the second half of November, compared with 880,000 in the previous two-week period. Mills crushed 14.57 million tonnes of cane versus 21.29 million tonnes in the first half of the month, Unica said. Ethanol production was 744 million liters compared with 1.08 billion liters in the previous two-week period. Sugar content in cane fell because of excess moisture. Unica said cane processed late in November had TRS (total recoverable sugar) of 120 kg per tonne, compared with 136 kg/T in the same period a year earlier. Mills continued to favor ethanol production over sugar, as the fuel still gives then better financial returns. They earmarked 68.5 percent of the cane to ethanol making late in November and 31.5 percent to sugar production. See below detailed figures from Unica's crop report for the second half of November (cane and sugar in million tonnes, ethanol in billion liters, total recoverable sugar-TRS in kg per tonne): BRAZIL'S CENTER-SOUTH - 2ND HALF OF NOV (ANNUAL COMPARISON) 2017/18 2018/19 PCT CHANGE CANE CRUSH 15.27 14.57 -4.54 SUGAR OUTPUT 0.73 0.53 -27.49 ETHANOL OUTPUT 0.80 0.74 -7.28 TRS (kg/T) 136.77 120.62 -11.81 CANE TO SUGAR 36.58 pct 31.50 pct BRAZIL'S CENTER-SOUTH CUMULATIVE DATA - 2017/18 VS 2018/19 2017/18 2018/19 PCT CHANGE CANE CRUSH 570.17 544.32 -4.53 SUGAR OUTPUT 35.20 25.76 -26.82 ETHANOL OUTPUT 24.53 29.09 18.57 TRS (kg/T) 137.51 139.09 1.15 CANE TO SUGAR 47.12 pct 35.71 pct Source: Cane Industry Group Unica (Reporting by Marcelo Teixeira; Editing by Steve Orlofsky)