One of the world's richest men, Mr Mittal, led the opposition of his neighbours when the house builder applied for permission to put up an apartment block in The Bishops Avenue, Hampstead. After the approval of the plans, Mr Mittal has put his stately 'Summer Palace' on the market. The luxury flat is being marketed at between 4 million pounds and 11 million pounds, the Daily Telegraph reported. Trevor Abrahmson, of Glentree Estates, one of two agents selling the property, said, ''The Bishops Avenue is a global name. It is well known to the international wealthy and for them to have a house here is the ultimate status symbol.''