Royal Bank of Scotland, which owns Coutts, the London-based private bank, is considering a rights issue to strengthen its weakened balance sheet. The move comes after months of speculation that the UK's second biggest bank would have to appeal to shareholders for money. RBS is part of a consortium of European banks which defeated UK rival Barclays to buy ABN Amro, the Dutch banking group, last year. Various media reports say that RBS has decided to tap shareholders for capital due to worsening sub-prime write-downs and said this would put chief executive Sir Fred Goodwin under pressure, as he has repeatedly insisted RBS does not need new capital. The capital call would also make RBS's involvement in buying ABN Amro looked increasingly unwise. The move is believed to have been prompted by further sub-prime provisions on top of the £2.4 billion ($4.8 billion) already reported and government pressure for the banks to strengthen their balance sheets in return for an offer of much-needed liquidity, according to the Daily Telegraph. The rights issue will put Sir Fred under pressure, the newspaper said. Some shareholders have indicated that they will demand his resignation in return for providing fresh capital. A dividend cut would also anger them, particularly after RBS attempted to silence criticism of its strategy at its results in February by saying it would raise its dividend. The bank is expected to unveil plans at its annual meeting next Wednesday. It was unclear how much fresh capital RBS might seek, but it is likely to be a substantial sum. Analysts at UBS calculate that RBS needs an additional £9 billon merely to bring its capital ratios into line with other UK banks, the Financial Times said. A rights issue by RBS would mark the first significant reaction to the credit squeeze by a European bank aside from UBS, the Swiss bank that has suffered heavy losses. European banks’ reluctance to issue capital is in stark contrast to lenders in the US, which have been faster to replenish their capital.