Stocks edge up, but concern over corporate results persists

By Patrick Graham LONDON (Reuters) - A rise in oil prices and gains for some European banking shares helped prod stock markets into positive territory on Tuesday, in a week dominated by what second-quarter corporate earnings will say about the state of global markets and growth. Investors found just about enough optimism in oil prices holding above $40 a barrel, as well as Italy's plans for a $5 billion fund to deal with bad debts, to turn indexes positive by midday in London. "The Italian bank