Banks check Chinese walls as Hannam appeal reveals cracks LONDON (Reuters) - The name of the top London banker fighting to overturn a fine for market abuse is coming up in conversations between lawyers and their clients, who are asking: "Is this a Hannam?." Extra caution over potential conflicts of interest within corporate broking is what Britain's much criticized financial regulator hoped for when it imposed a 450,000 pound ($667,400) penalty on JPMorgan (JPM.N) dealmaker Ian Hannam last year. Ironically, it is Hannam's appeal to overturn the fine and restore his reputation as a powerful dealmaker that has laid bare the ease with which bankers can casually leak potentially market-moving information and made the industry wary. If the 57-year-old former special forces soldier succeeds in persuading a tribunal that he did not pass on inside information, banking veterans might breathe a sigh of relief. But the case, which has been delayed until October, is prompting companies to look closely at their Chinese walls. A Chinese wall is a set of rules aimed at preventing those with sensitive information, for example a banker working on a company merger, from passing it on to others who could profit from it. "I think more care is being taken to formalize wall crossing, and not to assume the recipient of the information knows the score," said Rob Moulton at UK law firm Ashurst. The case against Hannam, whose multi-billion-dollar deals transformed Britain's blue-chip share index, does not question his integrity, but seeks to draw a line in the grey area of what constitutes acceptable business conduct. It also tests the ability of the three-month-old Financial Conduct Authority (FCA) to rein in lax controls and, where possible, target high profile individuals. The watchdog was spun out of a predecessor blamed for failing to halt risk-taking that helped fuel the financial crisis and misselling scandals. "I have now had clients ask me: 'Is this a Hannam sort of case?' when considering whether they are allowed to take someone over the wall, and to that extent, the publicity will have helped FCA's broader agenda," Moulton adds. The Hannam case hinges on two emails he sent in 2008 to Iraqi Kurdistan's oil minister Ashti Hawrami on behalf of a client, Heritage Oil (HOIL.L), which the regulator alleges included potential inside information. Hannam, who quit his job last year to fight the allegations, says the emails were too imprecise, and possibly inaccurate, to constitute insider information. "I either made it up or was putting a spin on it to get a meeting," Hannam said of one email at the London tribunal earlier this month. Hannam also argues that Hawrami, a former geologist, was an insider anyway - while conceding that formal insider lists were "not necessarily" kept at early stages of deals. Financial advisers and law firms are required to keep lists of those who know price-sensitive information. But some lawyers say that in the heat of a deal, such rules are easily breached. So they are advising clients to be thorough and, when it comes to price-sensitive information, ensure they create records that show who knew what when - and do it "the boring way." "Whatever the outcome of these proceedings, those engaged in financial dealings ... will wish to consider much more carefully both their duties and obligations under the rule book," said James Carlton of law firm Fox Williams, adding that the Hannam case showed the FCA would no longer tolerate "what many have considered to be a very grey area for many years." The FCA, armed with fresh powers to hold bankers and institutions to account, is increasingly intrusive and hardline. It is asking more questions and ramping up demands for skilled persons reports, when companies are forced to pay for FCA-appointed independent experts to spot check or monitor their behavior - with the added threat of publicity. One lawyer branded these Section 166 orders a "corporate arrest." The FCA says the market is at last taking notice. Regulatory data on suspicious share price moves ahead of UK mergers and acquisition announcements has been a potential measure of how endemic misconduct such as insider dealing is in London. That rate, which had doggedly remained at 20 to 30 percent for years, slid to a record low of 14.9 percent in 2012. Additional reporting by Andrew Callus; editing by Philippa Fletcher