City sources predict the FTSE 100 will open up 14 points from yesterday's close of 5,405, tracking Asian stocks higher after Japan's economy expanded at an annualised rate of 4.1 percent in the first quarter of the year. Diversified mining group Vedanta Resources saw robust growth in revenue in the year to the end of March and said that it remains well-positioned to benefit from strong demand in emerging markets in the future. Revenue increased by 22.6% from $11,427.2m to $14,005.3m in the year ended March 31st, slightly below the consensus forecast of $14,172m.Higher gold prices and improved production volumes of copper and gold gave Antofagasta a boost in the first quarter of 2012. Group turnover rose 38.9% to $1,762m in the three months ended March 31st from $1,269m the year before, feeding through to group earnings before interest, tax, depreciation and amortisation (EBITDA), which rose 35.4% to $1,099m from $812m the year before.Aviva, the general insurer which recently lost its Chief Executive Officer (CEO) after a shareholder revolt over pay, says it has made a solid start to 2012. Operating profit for the first quarter of the year is marginally down on the corresponding period of last year, but stripping out the effects of the sale of car rescue service RAC and the de-consolidation of Delta Lloyd - which is no longer a subsidiary since the group sold down its stake - sees operating profit show a slight increase.