Electromagnetic Geoservices (EMGS) has been awarded a multi-year contract in south-east Asia worth up to $73.3m from "one of the world's largest national oil companies", it said.

EMGS' 103-metre research vessel Atlantic Guardian (built 2001) will be employed under the contract for up to two years, the shipowner said in a release on Tuesday.

"This letter of award from a repeat customer, together with the on-going proprietary acquisition in south-east Asia, has secured backlog for both of the company's vessels, providing a sound basis for two-vessel operation for the company in 2019," said Bjorn Petter Lindhom, EMGS' chief executive.

"It also gives us confidence that our strategy of integrating CSEM [controlled-source electromagnetic data] into oil companies' exploration workflow is on the right track."

The Atlantic Guardian's contract has a minimum value of around $29.3m, much of which will be recognised this year, EMGS said.

The call-off contract was awarded following a sole-sourced tender process that commenced in March.

Final execution of the contract will take place within around three weeks, EMGS said.

The company's other research vessel, Boa Thalassa (built 2008), commenced an offshore survey in south-east Asia on 23 March, according to EMGS' latest vessel update.

AIS data shows the vessel has been active off the north-west coast of Borneo since then.