Leading Scottish companies Forth Ports and Cairn Energy will demonstrate their abilities to soldier on as independent businesses this week as they await imminent takeover news.  Forth Ports, which has opened its books to potential bidders at the arcus infrastructure fund, is expected to produce a solid 10% lift in underlying annual profits to around ?36 million on Tuesday and will confirm robust trading at its six Scottish ports, as well as increasing activity at its Tilbury operations in the run up to the Olympics.  But most interest will centre around a revaluation of the group s docklands properties following planning consent for the harbour development, higher rental from the Ocean Terminal shopping centre and increasing potential for green energy developments.  Experts say this should lead to a sharp increase in current book ?74m value of the properties, although few expect a return to the ?285m valuation of 2008.  arcus already owns 23.5% of the shares and has indicated it is ready to offer the equivalent of ?16.50 a share for the rest, valuing the business at ?755m.  Followers at arbuthnot say it does not feel like a knock-out bid but better terms would depend on  bullish assumptions  on the landbank and energy opportunities.  Cairn Energy, which is waiting government approval to sell control of its main assets in India, could replace previous losses with annual profits of as much as ?362m on Tu