By Luke Jeffs LONDON, Jan 14 (Reuters) - ICAP has sold a stake intechnology unit Traiana to seven top banks in the latest exampleof the world's largest broker partnering with clients on keyprojects in a bid to retain their long-term support. ICAP said on Monday it had sold 12 percent of Traiana, whichsells systems to streamline traders' back offices, to the banksfor about $35 million. The banks are Bank of America Merrill Lynch,Barclays, Citigroup, Deutsche Bank, JPMorgan, Nomura and Royal Bank of Scotland. "Traiana's market leading technology assisted the foreignexchange industry in lowering the cost of processingtransactions, which helped us make the $4 trillion of dailyvolumes that you see today a reality," said Troy Rohrbaugh,global head of foreign exchange and rates trading at JP Morgan. The banks also struck a deal with ICAP whereby they can buyin the future an additional 20 percent of Traiana for $82.5million, they said. ICAP said it had changed Traiana's board to reflect the newownership structure with each of the banks taking a seatalongside the division's chairman Gil Mandelzis and chiefexecutive Andy Coyne. Traiana, which provides banks and other trading firms withsystems to automate post-trade processing and risk management,looks well positioned to tap reforms to make theover-the-counter (OTC) trading market more transparent. Regulators want to force more of the vast OTC market to useexchanges and clearing houses to tackle some of the problemsthat arose after the collapse in 2008 of Lehman Brothers, a bigOTC trader. This will change how banks and brokers process these trades which could create more demand for Traiana products. "Traiana is an increasingly important firm for us and ourclients," said Thomas Gillie, co-head of G10 foreign exchangetrading at BofA Merrill Lynch. The Traiana sale is the latest example of ICAP sellingstakes in its key initiatives to clients. ICAP said in December Citigroup had joined Barclays, BofAMerrill Lynch, Deutsche and JP Morgan as an investor in thebroker's swaps broking system i-Swap. The British broker also said last month the door is open toother participants in i-Swap.