Sky has commissioned a second series of crime thriller Fortitude.

Writer Simon Donald and executive producers Patrick Spence and Frith Tiplady, will return for a new 10-part series on Sky Atlantic.

The current series, which airs its 11th and final episode on Thursday night, stars Michael Gambon, Christopher Eccleston and Call the Midwife’s Jessica Raine.

None of the cast for the second series have been announced ahead of the final episode, but Sky head of drama Anne Mensah, who is also an executive producer on the show, said she expects those who make it to the end of the series alive to return.

“Simon is head down writing and we won’t shoot for a while,” she said. “We love the cast, particularly the ones that survive.”

Fortitude cost Sky £25m and is produced by Tiger Aspect and Fifty Fathoms.

The series premiere was watched by 2.7 million within seven days of airing and averaged out at 1.7 million per episode. Sky said half of Fortitude’s viewers were watching Sky Atlantic for the first time.

Sky Atlantic channel director Zia Bennett said: “Simon Donald created a unique and unsettling story which, week after week, has captivated our customers. I am absolutely delighted that we will be bringing Fortitude back next year with a story that promises to engage, challenge and enthral us all over again.”

Fortitude premiered simultaneously across the five markets in which Sky operates: Italy, Germany, Austria, the UK and Ireland.

Sky said Fortitude was also the most successful show for its Sky Vision distribution arm, selling to more than 100 broadcasters including ABC Australia, Superchannel in Canada and Canal+ in France.

Mensah said the success of the big-budget shows around the world with other broadcasters helped justify the outlay.

“By making things that are really quality, and feel original in the marketplace, it means there’s a reinvestment back into Sky,” she said.

In 2011, Sky chief executive Jeremy Darroch said he wanted Sky to spend £600m on original British content by 2014, a target the company has met.

Sky is continuing to invest in original commissions, including The Last Panthers starring John Hurt and Samantha Morton and Critical, a hospital drama from Line of Duty creator Jed Mecurio.