London's leading shares have opened firmer, encouraged by reports that the world's central banks stand ready to act should financial markets freeze up next week in the wake of Greece's general election on Sunday.Global monetary authorities are ready in the event that liquidity is required to ensure that there is sufficient cash is flowing through the financial system, G20 officials told Reuters. According to the news agency, a "senior G20 aide familiar with discussions among international financial diplomats" said: "The central banks are preparing for coordinated action to provide liquidity." His statement was reportedly confirmed by "several other G20 officials".Banks boosted by ECTR initiativeBanks are wanted after the UK government and the Bank of England announced multi-billion pound plans to get banks lending more to companies. The move comes as the UK economy has stalled, with recent indicators pointing to the country remaining in recession for a third quarter. Chancellor George Osborne said the plan, which reports have valued at between £80bn - £140bn, showed the UK was "not powerless in the face of the eurozone debt storm".A second scheme, called Extended Collateral Term Repo (ECTR) Facility, will give banks access to short-term money to manage "exceptional market stresses". The latter scheme will see the Bank of England allocating a minimum of £5bn every month to banks in the form of six month loans.The news sent investors scurrying off to load up on shares in banks, especially Royal Bank of Scotland, Lloyds Banking and Barclays.Trade me share price down, sportTemporary power and temperature control specialist Aggreko is getting a shoeing despite highlighting the boost it expects to get in the second half of the year from the London Olympics.The problem is that in the first half of the year, revenue growth has slowed down in the second quarter. The group said it expects first half underlying group revenue will grow by around 15% and trading profit by around 20%, indicating a slow-down from the first quarter performance when both its International Power Projects and Local divisions delivered underlying revenue growth of more than 20%.Also getting chopped down inside the box are pay TV operators BSkyB and BT in the wake of the eye-watering sums paid by both to the Football Association for the rights to televise live matches from the Premiership.Board room shuffleDoing the board room shuffle today are accountancy software titan Sage and troubled specialist engineering services provider.Sage's Chairman, Tony Hobson, has decided it is time to give up the chair to make way for Donald Brydon, currently chairman of medical devices maker Smiths Industries. Brydon will join Sage's board as a non-executive director on July 6th to get his feet wet prior to taking over from Hobson at the beginning of September.Lamprell, meanwhile, has moved quickly to replace Jonathan Silver, who announced earlier this month his intention to give up the Chairman role to become Deputy Chairman. The new guv'nor is industry veteran John Kennedy who, until US conglomerate General Electric took it over, was Chairman of Wellstream Holdings.FTSE 100 - RisersRoyal Bank of Scotland Group (RBS) 244.10p +6.41%Lloyds Banking Group (LLOY) 31.08p +4.47%Barclays (BARC) 200.65p +4.10%Vedanta Resources (VED) 937.50p +3.82%Weir Group (WEIR) 1,452.00p +3.71%Kazakhmys (KAZ) 715.00p +2.80%Evraz (EVR) 262.80p +2.78%Eurasian Natural Resources Corp. (ENRC) 401.40p +2.71%Fresnillo (FRES) 1,490.00p +2.62%Man Group (EMG) 70.90p +2.53%FTSE 100 - FallersAggreko (AGK) 2,072.00p -4.07%BT Group (BT.A) 198.30p -1.69%ARM Holdings (ARM) 494.70p -1.45%British Sky Broadcasting Group (BSY) 662.00p -1.34%Centrica (CNA) 308.70p -1.22%Experian (EXPN) 927.00p -1.01%Next (NXT) 3,086.00p -0.77%Smith & Nephew (SN.) 607.50p -0.65%National Grid (NG.) 656.00p -0.61%AstraZeneca (AZN) 2,683.00p -0.61%FTSE 250 - RisersLamprell (LAM) 87.80p +11.07%Imagination Technologies Group (IMG) 466.30p +6.88%New World Resources A Shares (NWR) 320.20p +6.34%Essar Energy (ESSR) 117.30p +5.01%Ferrexpo (FXPO) 189.90p +4.17%Bumi (BUMI) 324.00p +3.68%Ruspetro (RPO) 133.20p +3.66%Barratt Developments (BDEV) 130.00p +3.34%Northgate (NTG) 168.40p +3.31%Exillon Energy (EXI) 89.55p +3.17%FTSE 250 - FallersLondon & Stamford Property (LSP) 104.10p -2.71%Bodycote (BOY) 341.90p -2.31%Supergroup (SGP) 271.60p -1.24%Carpetright (CPR) 680.00p -1.16%TR Property Inv Trust Sigma Shares (TRYS) 62.60p -1.11%Wetherspoon (J.D.) (JDW) 395.60p -1.10%UK Commercial Property Trust (UKCM) 68.55p -1.08%PZ Cussons (PZC) 336.50p -1.03%Euromoney Institutional Investor (ERM) 747.50p -0.99%Devro (DVO) 307.00p -0.94%JH