Traffic engineering (TE) functionality aims to control and fine-tune the routing configuration and bandwidth allocation in order to optimize the use of network resources and avoid the build-up of congestion. The performance of a given TE scheme is, however, strongly influenced by the degree of flexibility offered in distributing the traffic load. Multipath routing coupled with arbitrary traffic splitting are two essential ingredients for achieving the desired flexibility. Current proposals for multipath routing in OpenFlow have mostly focused on equal splitting solutions, which impose limitations in terms of the level of control that can be achieved. In this paper, we investigate a new approach, which exploits the properties of bit-masking operations to enable flexible TE in OpenFlow networks. The proposed solution relies on the matching entry feature and the multiple table pipeline capability of OpenFlow, and as such, is in line with the current standard. Based on empirical evaluation, we illustrate the influence of the considered masking parameters and how these can be configured to achieve the desired traffic splitting ratios. The results demonstrate that our solution can achieve a similar level of splitting accuracy as the one obtained with a hash-based approach. However, in contrast to current proposals, it does not require complex extensions to the OpenFlow protocol and can be easily implemented in an OpenFlow environment.