Nikkei steady, exporters rise on weak yen, financials retreat

* Exporters rise as USD stays above 100 yen * Non-life insurers, banks give up gains after rallies * Nikkei likely to trade at 15,500 at year-end - UBS By Ayai Tomisawa TOKYO, Nov 20 (Reuters) - Japan's Nikkei share average was flat on Wednesday morning as recent outperformers including banks and non-life insurers pulled back, offseting gains in exporters after the dollar traded above 100 yen. The Nikkei was steady at 15,122.05 in mid-morning trade after gaining as much as 0