This paper proposes an extension to IEC 61499 architecture to better support flexibility and reconfigurability of automation systems while reducing communication overhead. The extension concerns adapter connections between function blocks. It aims at improving the performance of popular "one-line engineering" design pattern. The current adapter connections are supporting one-to-one links between function blocks, through which a bi-direction flow of events and data takes place. The proposed extension, called bus, allows many-to-many connections, i.e., several function blocks can be connected to several function blocks sending and receiving events and data simultaneously. Before implementing the extension by means of compiler and editor, it was prototyped using an existing means of IEC 61499, as a composite function block with several inputs - adapter sockets and outputs - adapter plugs. The prototyping shows feasibility of the proposed extension.