Michael Spencer, the founder and chief executive of interdealer broker Icap, has admitted to using shares in broker Numis, a company he chairs, as collateral for a loan to a private investment company he owns a majority stake in, after previously believing it unnecessary to disclose the information.

According to a statement released this morning, Spencer pledged 13,102,934 ordinary shares in Numis, registered in the name of Spencer's private investment company IPGL, as collateral for a loan from HSBC. The loan facility agreement was signed on October 6, and replaced a similar agreement, under which Numis shares were also pledged, signed on January 22 this year.