Cemex Asia Holding Ltd has named JP Morgan Securities as its financial advisor in its plan to sell its 25.53 per cent stake in state cement company PT Semen Gresik, a report said today.  JP Morgan is still seeking prospective buyers of the stake, bankers told the newspaper Bisnis Indonesia. Cemex has opted to sell the stake and plans to build a new cement factory in the country ending its long dispute with the government, observers said.  Cemex has also filed lawsuit against the government for failure to honor a put option contract, which requires the government to sell more stake if requested by Cemex.