BUZZ-Cairn Energy: Erosion of Cairn India stake chips away at stock
** Oil explorer's shares down as much as 2.7 pct after co reported a wider after-tax H1 loss
** Traders attribute fall to the lack of a meaningful update on Cairn India (BSE: CAIRN4.BO - news) issue and continued weakness in crude prices
** Co takes $177 mln impairment on erosion in value of c.10 pct stake in Cairn India
** Co restricted from selling Cairn India stake, valued at $525.5 million at June 30, due to tax dispute with Indian government
** A quarter the stock's daily avg volume traded in the first hour, dragging FTSE 350 oil and gas index down with it (abhiram.nandakumar.thomsonreuters.com@reuters.net)