* Shares highest since 1990
* Net profit up 15 pct, beats forecasts
* Loan losses sharply lower
* Launches share buy-backs, keeps dividend policy (Adds CEO, share, analyst)
By Gwladys Fouche and Terje Solsvik
OSLO, July 12 (Reuters) - Shares in DNB hit a 27-year high on Wednesday as Norway's largest bank beat second-quarter earnings expectations with higher lending margins and lower loan losses.
DNB is benefiting from Norway's healthy economy, with lower unemployment in all regions, even areas where the crisis-hit energy sector is predominant.
Net profit rose 15 percent to 5.24 billion crowns ($633.39 million), while analysts polled by Reuters had expected flat earnings.
"There is profitable growth in all customer segments, and our customers make sure that we have lots to do across the board," Chief Executive Rune Bjerke said in a statement.
"Combined with low impairment losses during the quarter, this makes us satisfied," he said.
DNB's lending losses amounted to 597 million crowns, well below the 1.31 billion forecast by 16 analysts polled.
"Those who were laid off in the oil and gas sector have been absorbed in other sectors. It has happened effectively and it has been happening fast," Bjerke told Reuters.
Its crown currency has weakened by some 30 percent against the euro in the past five years, strengthening the competitiveness of Norway's exports including aluminium and fertilisers.
Rising public sector spending, underpinned by Norway's $855-billion sovereign wealth fund, has also supported demand and consumption.
"I am quite positive," said Bjerke. "We speak to our customers a lot and a majority of them are positive and see better results, and they are positive about the employment situation in their own companies."
The bank announced a share buy-back plan and said it would maintain its plan to pay more than half of its 2017 earnings in dividend.
It also reiterated its 2016-2018 outlook for loan losses of up to 18 billion crowns by 2018. Those losses have reached 8.6 billion crowns.
"We will bring more information to our investors after digesting the numbers," Bjerke told an earnings presentation. "We are going to be more specific when we have our capital market day (in November)."
DNB shares hit a high of 149.5 crowns on Wednesday, their highest level since 1990. They were up 4.6 percent at 148.7 crowns at 1054 GMT.
The stock is up 62 percent over the past 12 months, outpacing a European banking index up 44 percent.
$1 = 8.2729 Norwegian crowns Reporting by Gwladys Fouche and Terje Solsvik; editing by Jason Neely