Nikkei held below peak, Greece uncertainty keeps investors cautious
* Nikkei has gained 2.5 pct for the week * Market awaits nervously but expects resolution without Grexit - trader * Japan's upbeat eco**mic data gives little surprise - analysts By Ayai Tomisawa TOKYO, June 26 (Reuters) - Japan's Nikkei share average dropped on Friday as investors took profits in a market that hit its highest levels since late 1996 earlier this week, opting for caution while uncertainty hung over whether Greece would manage to avoid defaulting. The Nikkei sh