Abstract
Let $M$ be a module over a commutative ring $R$ and $U$ a nonempty proper subset of $M$.
In this paper, the extended total graph, denoted by $ET_{U}(M)$, is presented, where $U$ is a
multiplicative-prime subset of $M$. It is the graph with all elements of $M$ as vertices, and for distinct $m,n\in M$, the vertices
$m$ and $n$ are adjacent if and only if $rm+sn\in U$ for some $r,s\in R\setminus (U:M)$. We also study the two (induced) subgraphs $ET_{U}(U)$ and $ET_{U}(M\setminus U)$, with vertices $U$ and $M\setminus U$, respectively. Among other things, the diameter and the girth of $ET_{U}(M)$ are also studied.