  Motivated by recent developments in the metrical theory of continued
fractions for real numbers concerning the growth of consecutive partial
quotients, we consider its analogue over the field of formal Laurent series.
Let $A_n(x)$ be the $n$th partial quotient of the continued fraction expansion
of $x$ in the field of formal Laurent series. We consider the sets of $x$ such
that $\deg A_{n+1}(x)+\cdots+\deg A_{n+k}(x)~\ge~\Phi(n)$ holds for infinitely
many $n$ and for all $n$ respectively, where $k\ge1$ is an integer and
$\Phi(n)$ is a positive function defined on $\mathbb{N}$. We determine the size
of these sets in terms of Haar measure and Hausdorff dimension.
