Singer Capital Markets has upgraded its rating on engineering software firm Aveva Group after a strong end to the year and a confident outlook for the current year.The group's full-year results were ahead in terms of revenue performance but were in line on an adjusted pre-tax profit and earnings per share basis, Singer said.As a result, the broker moves its rating to 'fair value', from 'sell', and raises the target price to 1,500p, from 1,250p.Full-year results at Electrocomponents were in line, according to Peel Hunt, who raises its target price from 295p to 315p to reflect a confident outlook and expectation of continuing outperformance.The electronics and maintenance products supplier reported headline pre-tax profit ahead of the broker's estimates for the year ended 31 March. Current trading is said to be strong, with underlying sales 16% ahead of the prior year."Whilst there is nothing in these numbers that we feel will drive the shares materially higher in the short term, we think this remains a stock to 'buy'," said analyst Henry Carver.Matrix has placed its rating on Northern Petroleum 'under review' after a disappointing update in which the oil and gas firm slashed reserve estimates at three of its five gas fields in the Netherlands."This is a disappointing update, particularly from a generally conservative company. We still see considerable value in the underlying reserve base (provided it can be relied on) and the strong balance sheet, and so we think that industry interest is likely to be stimulated by this news in a weak market," Aliyev added.However, for now, the rating and target price is placed 'under review'.---BC