SINGAPORE (Reuters) - Brent futures fell more than $1 to slip below $108 a barrel on Friday as investors waited for key U.S. economic data to gauge the demand growth outlook for oil with rising supplies weighing on prices. The world's biggest economy likely grew at a 1.9 percent annual rate in the third quarter, according to a Reuters poll, but still well short of the pace economists say is needed to ensure steady recovery. Brent has fallen more than 3 percent this month in part on investor reluctance to lock in fresh positions ahead of U.S. elections. Brent crude had slipped $1. ...