ATLANTA (Reuters) - Boeing Co <BA.N> said on Thursday that its 787 Dreamliner would make its first flight by the end of this year, with the first delivery expected in the fourth quarter of 2010.

The plane maker said it has concluded that the initial test-flight planes of the long-delayed 787 have no commercial market value because of necessary modifications that have been made.

It added that costs previously recorded for the first three test planes would be reclassified as research and development expense, resulting in an estimated pretax charge of $2.5 billion, or $2.21 a share, against results for the third quarter.

The aircraft, already two years behind its original schedule, was to fly in the second quarter of 2009, but the flight was delayed so Boeing could address a structural problem.

The company's shares rose 5.6 percent in premarket trade.

(Reporting by Karen Jacobs, editing by Gerald E. McCormick)