City experts said Skanska was at fault for the collapse in profitability and subsequent redundancies because it had diversified too much and had made too many acquisitions too quickly.
Skanska's operating profit is expected to fall to £136m, compared with £290m last year, and it has announced 3500 job losses, mainly in Poland.
Bjork announced the heavy losses in its Polish operations at a briefing last week but was unrepentant about the overall global strategy.
Bjork said: "A lot of the losses have to do with a few markets. We are on track with those few exceptions.
"I am confident that we have things under control."
He added that the problems had been hard to predict, but had been dealt with in a forceful way once they were identified.
He said that taking the losses now had put the group in a sound position. "It gives us a good base from which to grow profitability."
Analysts criticised the timing of Skanska's move into Poland last year but Bjork said it remained an important market and would bounce back.
They also expressed concern about Skanska's "hands-off " management style. They said this left it vulnerable to heavy losses, because it did not have control of the accounts of its businesses.
One analyst said: "You need to know what the business is bidding for and for how much, otherwise you can lose track and get hurt by a big loss. It's what happened to Laing."
Bjork also moved to allay analysts' concerns and industry speculation that Skanska's UK operations were struggling.
Earlier this year, the firm revealed losses of £13m on UK joint venture contracts with Costain and Mowlem.
Skanska has refused to identify the contracts involved but Building understands that they included the £124m A2/M2 widening scheme for the Highways Agency.
Bjork said the losses were incurred before it bought Kvaerner last year and would not lead to further provisions.
He insisted: "We have a terrific business in the UK and it is doing very well."