Holcim AG's Particim subsidiary further reduced its stake in Cimpor Cimentos de Portugal SA to 0.62 per cent by selling 20.000 mln shares to C+PA - Cimento e Produtos Associados, Canal de Negocios cited Cimpor as saying.  The price was not disclosed.  Cimpor said Holcim now has 4,224,995 shares, giving it 0.62 per cent of capital and 0.634 per cent of voting rights, the report said.  The Swiss cement maker, which at one time held 10 per cent of Cimpor, cut its holding to 3.6 per cent in October and said it would sell the rest when there was a good opportunity.  Cimpor also said C+PA - Cimento e Produtos Associados now has 4.552 per cent of its shares, after acquiring the 20 mlllion from Cimpor in an off-market deal and buying a further 8000 on the market, Canal de Negocios said.