London open: Ex-div stocks offset a surging Admiral

- Admiral surges 11 percent on full-year results.- Ex-div stocks provide a drag.- Greek debt-swap deadline looms.Following the 2.8 percent tumble over the last three days, the Footsie opened broadly flat on Wednesday ahead of tomorrow's deadline for the Greek debt-swap. A surge in the share price of Admiral was offset by some heavyweight blue chips going ex-dividend.Europe is awaiting a final decision this week on the Greek debt restructuring. Private investors have a March 8th deadline to decide if they will accept a debt exchange in which they will be required to take a 53.5% haircut in an agreement that would save Athens about €106bn (£88bn). The Greek government is optimistic that the rate of participation in the bond-swap could reach between 75% and 80%, according to sources cited by the Wall Street Journal. However, this falls short of the 90% participation rate needed to avoid the trigger of collective action clauses (CACs). Nevertheless, a growing number of big banks have said that they will participate in the deal, including giants Societe Generale, Generali and UniCredit. Greek banks are also said to be willing to accept.ADMIRAL RACES AHEADCar insurance giant Admiral surged early on after deciding to pay a special dividend as it seeks to curb the number of high value bodily injury claims which have dented recent figures. Admiral has revealed that pre-tax profits up 13% on 2011 at £299m with net revenue up 36% at £870.3m. Both those figures beat the consensus forecast of £291m and £849m, respectively.Banking titan HSBC's sale of peripheral parts of its operations has continued with the sale of its general insurance businesses in Hong Kong, Singapore, Argentina and Mexico. Shares rose moderately, while peers Royal Bank of Scotland and Lloyds were among the fallers.Power systems giant Rolls-Royce edged higher after announcing that it will soon begin flight tests of an engine upgrade for the US Air Force's T56 turboprop engine.British American Tobacco was the heaviest faller after trading without the right to its latest dividend. Other big movers that went ex-dividend this morning include FTSE 100 peers CRH, Serco and Standard Chartered and FTSE 250 stocks TUI Travel, Spirent Communications, Domino Printing Sciences and Renishaw.Miners were providing a lift after their recent poor performance with Kazakhmys, ENRC, Rio Tinto and BHP Billiton rising strongly.FTSE 250: COBHAM SURGES AFTER HIKING DIVIShares in defence technology group Cobham jumped after raising its full-year dividend by a third on the back of strong profits and cash generation in 2011. While revenue fell 3%, the group gave an optimistic outlook for defence spending in the US.Development, environmental and energy resources consultancy RPS Group fell despite seeing full-year pre-tax profits come in marginally ahead of expectations. Afren was making gains after well test results at its Okoro East oil discovery, offshore Nigeria, confirmed high quality oil in excellent reservoir sands. Future horizontal production wells at the project will be capable of yielding 4,500-7,000 barrels of oil per day each, the group predicts.BCFTSE 100 - RisersAdmiral Group (ADM) 1,158.00p +11.35%BAE Systems (BA.) 309.00p +1.61%IMI (IMI) 946.00p +1.39%Essar Energy (ESSR) 103.00p +1.38%Petrofac Ltd. (PFC) 1,564.00p +1.23%Randgold Resources Ltd. (RRS) 6,925.00p +0.95%Meggitt (MGGT) 383.80p +0.87%Kazakhmys (KAZ) 932.00p +0.87%Whitbread (WTB) 1,650.00p +0.79%Smiths Group (SMIN) 1,044.00p +0.77%FTSE 100 - FallersBritish American Tobacco (BATS) 3,098.50p -2.91%CRH (CRH) 1,255.00p -2.33%Royal Bank of Scotland Group (RBS) 25.59p -2.22%Barclays (BARC) 234.10p -2.01%Lloyds Banking Group (LLOY) 33.53p -1.83%Standard Chartered (STAN) 1,545.50p -1.25%Serco Group (SRP) 513.50p -1.06%Vedanta Resources (VED) 1,334.00p -0.82%Xstrata (XTA) 1,116.50p -0.80%Ashmore Group (ASHM) 373.30p -0.69%FTSE 250 - RisersCobham (COB) 200.10p +7.41%JD Sports Fashion (JD.) 810.00p +3.85%Perform Group (PER) 280.00p +3.70%Drax Group (DRX) 509.00p +2.81%Melrose (MRO) 379.40p +2.51%Spirit Pub Company (SPRT) 56.75p +2.25%Jupiter Fund Management (JUP) 244.40p +2.00%Dairy Crest Group (DCG) 327.60p +1.99%Oxford Instruments (OXIG) 1,165.00p +1.75%Afren (AFR) 127.80p +1.75%FTSE 250 - FallersTUI Travel (TT.) 187.70p -2.85%Spirent Communications (SPT) 147.30p -2.71%Domino Printing Sciences (DNO) 642.00p -2.28%Unite Group (UTG) 191.60p -2.19%Filtrona PLC (FLTR) 435.10p -1.78%Wood Group (John) (WG.) 693.00p -1.77%Renishaw (RSW) 1,376.00p -1.64%COLT Group SA (COLT) 100.00p -1.48%Elementis (ELM) 174.40p -1.47%Tullett Prebon (TLPR) 313.00p -1.45%