Shareholders in TUI AG, TUI Travel back merger deal

* TUI AG (Xetra: TUAG00 - news) , TUI Travel (LSE: TT.L - news) agreed terms of merger in September

* Plan to create world's largest leisure tourism group

* 99.85 pct of TUI AG shareholders vote in favour of merger

* 80 pct of TUI Travel shareholds vote in favour (Updates with details of TUI Travel vote)

HANOVER, Germany,/LONDON Oct 28 (Reuters) - Shareholders in both German travel and tourism group TUI AG and British travel group TUI Travel on Tuesday approved the pair's plans to merge.

The two reached an agreement in September on the terms of a 6.5 billion euro ($8.3 billion) merger to create the world's largest leisure tourism group.

The tie-up had been expected ever since TUI Travel was created in 2007 from the merger of Britain's First Choice and the travel business of TUI AG, which already owns around 55 percent of the London-listed company.

At TUI AG's extraordinary general meeting in Hanover, shareholders representing 99.85 percent of TUI shares voted in favour of the merger, when at least 75 percent was needed for the deal to go ahead.

In London, shareholders representing 80 percent of TUI Travel shares backed the merger.

"The resolutions contained in the notice of the Court Meeting and Notice of General Meeting were duly passed by the requisite majorities," TUI Travel said in a statement.

Failure to agree the deal would have meant a huge setback for CEOs Friedrich Joussen and Peter Long.

The merger is expected to result in 170 million euros of costs savings and tax benefits and will streamline a cumbersome holding structure that includes headquarters in both Britain and Germany and two separate stock market listings.

"We as shareholders are very happy," Marc Tuengler of retail investor association DSW said earlier on Tuesday, citing the merger's solid industrial logic.

($1 = 0.7877 euro) (Reporting by Peter Maushagen; Writing by Maria Sheahan and Sarah Young; Editing by Georgina Prodhan and William Hardy)