Sept 24 (Reuters) - Australian shares are set to open slightly lower on Tuesday, tracking a lackluster Wall Street as mixed U.S. economic data kept risk sentiment in check. U.S. employment in the services sector shrank for the first time in nine-and-a-half years in September, but data also showed manufacturing activity rose in September, topping expectations. The local share price index futures fell 0.1%, a 25.7-point discount to the underlying S&P/ASX 200 index close. The benchmark rose 0.3% on Monday. New Zealand's benchmark S&P/NZX 50 index rose 0.1% in early trade. (Reporting by Soumyajit Saha in Bengaluru Editing by Chris Reese)