FRANKFURT (Reuters) - German car parts maker Continental said on Thursday it was postponing the planned spin-off of its powertrain unit Vitesco Technologies, citing ongoing economic uncertainty for the delay. The spread of the coronavirus has hammered equity markets, playing havoc with valuations, a factor which has already led Italy's CNH Industrial to say it may need more time to spin off its Iveco trucks unit."The spin-off requires better market conditions," Continental said in a..