BERLIN, Jan 29 - German wholesale sales fell in December in real terms by 0.5 percent month-on-month, leaving the annual change for 2003 at a gain of 0.1 percent, the first increase since 2000, data showed on Thursday. From December 2002, wholesale sales in real terms advanced 2.9 percent, the Federal Statistics Office said. In nominal terms in December, wholesale sales fell by 0.7 percent month-on-month and rose by 3.0 percent year-on-year, the office said. Wholesale sales in 2003 rose by 0.9 percent in nominal terms from the previous year, after a drop of 4.4 percent in 2002. In real terms in 2002, sales fell 3.6 percent.//