Members of Microsoft Corp's board have held talks with ValueAct Capital Management LP in recent days over the activist shareholder's demands to secure a seat on the company's board,two sources close to the matter said on Friday. ValueAct,which wants a say in the way the world's largest software company is adapting to the new world of mobile computing,is seeking to nominate a person from its own organization,the sources said. The news comes as Microsoft had its biggest sell-off in four years,wiping $34 billion off its market value,after quarterly results were hit by weak demand for its latest Windows system and poor sales of its Surface tablet.