The world's biggest seismic survey vessel owner, Shearwater GeoServices, has expanded again in a $127.5m move to take over the former fleet of bankrupt rival Polarcus.

The Norwegian company is adding six ships to its fleet of 21, as well as spending another $50m on streamers and related seismic equipment.

In March, Norwegian shipowner and investor Tom Steckmest emerged as chairman of the companies in control of the former Polarcus ships, which are between 88 loa and 92 loa and built between 2009 and 2012.