Sisu Capital, a little-known distressed company investor, has hired Lazard to help it block a controversial £381.5m (€572.2m) refinancing proposal for Welcome Break and launch a takeover of the struggling UK motorway services provider.

Sisu Capital, led by Joy Seppala, chief executive, is planning on Thursday to use its controlling stake in the junior bonds of Welcome Break to thwart the refinancing proposal tabled by Investcorp, the UK investment group. Advised by Lazard and law firm Bingham McCutcheon, Sisu Capital will pursue a full takeover of Welcome Break in a joint venture with Swayfields, a private company which operates rival motorway services brand Extra.