UPDATE 1-Mail order firm Otto buys Quelle's Russian ops

* Otto buys trademark rights for Quelle brand portfolio

* Acquires Quelle Russia business

* Otto pays double-digit million euro sum -source (Adds detail and background)

FRANKFURT, Nov 5 (Reuters) - Germany's Otto, the world's largest mail-order company, has struck a deal to buy the Russian business and trademark rights of its insolvent local peer Quelle, it said on Thursday.

Quelle, which is part of Arcandor's (AROG.DE) mail order business Primondo, is shutting down after more than 80 years in business, having failed to find a new investor. [ID:nLK439826]

Otto paid a double-digit million euro sum for the deal, a source close to the negotiations told Reuters.

Otto and Quelle did not disclose the size of the deal.

Quelle has 280 staff and annual sales of 170 million euros ($251 million) in Russia, while Otto makes sales of about 200 million euros a year there, which it says already makes it market leader.

Otto said it was not interested in any other parts of Quelle, for which talks with potential investors are continuing.