Nikkei lower, volatile commodities offset buying in autos

* Nikkei down but buying in autos continues - trader

* Greece woes hit sentiment - analyst

By Ayai Tomisawa

TOKYO, May 13 (Reuters) - Japan's Nikkei average edged lower on Friday as volatility in commodity prices and worries about Greece's debt problems offset buying in automakers.

Analysts said companies which have laid out clear plans on how they will recover their production after a quake in March, such as