The company's actions have since been criticised, with thousands taking to social media, saying it had intruded on "its territory", and killed for tourism.
"YOU HAD NO BUSINESS BEING ON THAT ISLAND. I hope decent people everywhere refuse to travel with you and you are forced into bankruptcy. It won't make up for the pure evil that you have done but it's a start," one person posted online in response to the company's Facebook post.
"Absolutely disgraceful. Though it is clear to see from your 'statement' above that the loss of the polar bear is of little significance to you. Your guards shouldn't be attempting to 'evict' the polar bear, you should be damn well leaving it alone, in its territory — stay on the ship," another person said on Facebook.
The company uploaded a Facebook post a day after the incident on Saturday, saying "it was necessary for the polar bear to be shot dead. We very much regret this incident."
"One of the guards was unexpectedly attacked by a polar bear that had not been spotted and he was unable to react himself," the post read.
"As the attempts of the other guards to evict the animal, unfortunately, were not successful, there had to be intervention for reasons of self-defence and to protect the life of the attacked person."
The unnamed guard in his 40s suffered head injuries and was flown by helicopter to Tromso hospital, he remains in a stable condition, the company said.
The company said excursions of this nature required staff to check areas before landing and to protect those on board against polar bear attacks.
"Landings are possible only in a few places; these are not there to serve the purpose of polar bear observation, on the contrary: polar bears are only observed from aboard ships, from a safe distance," it said in its Facebook post.
"To prepare for a shore leave, the polar bear guards go ashore in advance after sighting the landing site as a group and without passengers.
"They then set up a land station and check the area again to make sure that there are no polar bears in sight. As soon as such an animal approaches, the shore leave would be stopped immediately."
The company went on to say that Hapag-Lloyd Cruises had been travelling to "these destinations for many years with an experienced crew."
"We are extremely sorry that this incident has happened."
Despite its reasoning, it has been labelled "tourism at its absolute worst."
"Why don't you say you are very sad you killed a polar bear in its natural habitat and stop intruding in their home lands with tourists @HapagLloydAG?" a Twitter user said.
Polar bears have been protected in Norway since 1973 and nearly 1000 were counted on Svalbard during a 2015 census.
The archipelago, roughly twice the size of Belgium, lies about 1000km from the North Pole.
Five fatal polar bear attacks have been recorded on Svalbard in the last 40 years.
The most recent was in 2011 when a bear attacked a group of 14 people on a trip organised by a British schools association.
A 17-year-old Briton died and four other members of the expedition were hurt before the bear was killed.
