LONDON (Reuters) -Norway's sovereign wealth fund has backed UBS' plan to make its Additional Tier 1 (AT1) bonds, a form of debt, more appealing to investors by protecting them from a wipeout, and also signed off on UBS CEO Sergio Ermotti's pay package. The vote from the Norwegian fund, UBS' second-largest shareholder, at the bank's annual general meeting this week is a boost for UBS, which is seeking to prop up its capital buffers to satisfy Swiss regulators' demands as it integrates its former rival Credit Suisse. The bonds can be converted into equity or writt...