It posted pre-tax earnings of £2.9m ($5m) in 2013, against £0.61m in 2012, the Herald reported.

Revenue was up 40% to £36.9m.

The company, which runs a containership to the Northern Isles twice a week, recorded a big increase in demand for its services in connection with the new gas terminal being built on Shetland.

But directors added: "The group's container shipping service to Shetland and Orkney will suffer the withdrawal of Scottish government grant support.