UPDATE 1-Lufthansa CEO says to sign Air Berlin deal today

* Lufthansa CEO sees milestone in corporate history

* Source has said Lufthansa will buy Niki, LG Walter

* Air Berlin also in talks with easyJet

* Shares in Lufthansa rise nearly 3 pct (Adds further CEO comments, share price)

BERLIN, Oct 12 (Reuters) - Lufthansa will sign a deal on Thursday to buy parts of insolvent German carrier Air Berlin, Lufthansa Chief Executive Carsten Spohr said.

"We will see a milestone in the history of Lufthansa and Air Berlin today," he said.

Air Berlin, which has struggled to turn a profit over the last decade, filed for insolvency on Aug. 15, and a government loan has kept its planes in the air while it negotiates with potential buyers over parts of the business.

It said late last month that negotiations with Lufthansa and Britain's easyJet would continue until Oct. 12.

A person familiar with the matter had told Reuters on Wednesday that Lufthansa, Germany's largest airline, was set to buy Air Berlin's Niki leisure unit, its LG Walter regional airline and some additional short-haul aircraft.

Spohr said on Thursday he expected the imminent deal with Air Berlin to receive European Union approval by the end of the year, allowing operations to stabilise within about six to nine months.

Shares in Lufthansa rose 2.9 percent to 25.26 euros at the top of Germany's blue-chip DAX index in early trade after CEO Spohr's comments and upbeat notes from brokerages. (Reporting by Klaus Lauer; writing by Maria Sheahan; editing by Jason Neely and Victoria Bryan)