By Paolo Biondi ROME (Reuters) - Italian prime minister-designate Enrico Letta could announce a new government on Saturday and spell out its programme early next week, political sources said on Friday, while outgoing premier Mario Monti said he did not expect to be a minister. Letta, deputy leader of the centre-left Democratic Party, has been in discussions to iron out remaining differences with Silvio Berlusconi's People of Freedom (PDL) party following an initial round of talks on Thursday. ...