BERLIN, August 28, 2008 (AFP) - The German low-cost airline Air Berlin reassured markets on Thursday with the release of some positive first half results.

Core earnings gained 12.7 percent on a 12-month basis to 173.4 million euros (256.51 million dollars), a statement said.

Air Berlin also reduced its first-half net loss to 50.8 million euros from 60.4 million in the same period a year earlier, while sales gained 5.5 percent to 1.53 billion euros.

The group said first half net losses were 'typical,' while second half results which include the key summer season are normally more positive for airlines.

In the airline's second quarter, sales grew by 6.7 percent to 869.5 million euros and net profit gained 38.8 percent to 8.3 million.

Air Berlin boss Joachim Hunold was quoted by the statement as saying: 'We remain optimistic about achieving a positive operating income for the current year.'

Investors welcomed the results and pushed up Air Berlin's shares by 2.83 percent to 4.00 euros in early trading on the Frankfurt stock exchange.

The group has worried analysts after investing heavily to expand its operations before getting hit by higher fuel costs, which forced it to cut back on services and cancel some planned acquisitions.