UPDATE 2-Veteran German banker to become head of UBS wealth management

(Adds details)

ZURICH, Dec 14 (Reuters) - Veteran German banker Martin Blessing will replace Juerg Zeltner as the head of UBS's market-leading wealth management business at the turn of the year, Switzerland's biggest bank said on Thursday.

Blessing, former head of Germany's Commerzbank, has run UBS's Swiss business since September 2016. Zeltner, who has worked for UBS for more than three decades, will retire in 2018, the bank said in a statement.

The move sparked speculation that Blessing, 54, was now in pole position to succeed Chief Executive Sergio Ermotti, who has given no signs of wanting to stand down any time soon.

"There was already speculation that Blessing wouldn't remain the head of Swiss retail banking forever," said Zuercher Kantonalbank analyst Javier Lodeiro.

"This isn't likely to lead to a new strategic direction for wealth management. It will certainly take a few quarters until Blessing's new accents manifest themselves."

UBS Chairman Axel Weber, the former head of the Bundesbank, is also German.

UBS's wealth management business boosted pretax profit by 16 percent in the third quarter as net new money increased. It managed 1.1 trillion Swiss francs ($1.12 trillion) in invested assets as of the end of September.

Axel Lehmann, the current chief operating officer, will succeed Blessing as the head of UBS Switzerland. Sabine Keller-Busse will become chief operating officer and also be in charge of human resources.

"Lehmann will take over what is a well-run business," ZKB's Lodeiro said.

Zeltner's departure is the second major move in Swiss private banking within weeks after Boris Collardi abruptly quit his job as Julius Baer chief executive to join Geneva-based Pictet.

Baer declined to comment on whether Zeltner could be a CEO candidate.

($1 = 0.9850 Swiss francs) (Reporting by Michael Shields and Oliver Hirt; Editing by Amrutha Gayathri and Mark Potter)