Spanning cycles in regular matroids without M∗(K5)M∗(K5) minors

Catlin and Jaeger proved that the cycle matroid of a 4-edge-connected graph has a spanning cycle. This result can not be generalized to regular matroids as there exist infinitely many connected cographic matroids, each of which contains a M∗(K5)M∗(K5) minor and has arbitrarily large cogirth, that do not have spanning cycles. In this paper, we proved that if a connected regular matroid without a M∗(K5)M∗(K5)-minor has cogirth at least 4, then it has a spanning cycle.