BERLIN, Jan 14 - Germany's European Union harmonised consumer price inflation for December was slightly revised up to 0.9 percent month-on-month and to 1.1 percent year-on-year, according to final data released on Wednesday. Preliminary data reported last month showed a monthly gain of 0.8 percent and an annual increase of 1.0 percent. The Federal Statistics Office confirmed that Germany's national index of consumer prices rose by 0.8 percent month-on-month in December and by 1.1 percent on the year. The year-on-year figure marks a slowdown from November, when consumer prices rose 1.3 percent year-on-year. The Statistics Office confirmed average annual inflation in 2003 was 1.1 percent, down from 1.4 percent in 2002. The Office said that excluding heating oil and fuel, the national consumer price index was up by an average 1.0 percent last year.//