(Adds detail, context) BERLIN, Oct 26 (Reuters) - German real estate investor Adler Group has signed a term sheet for the sale of properties worth more than 1 billion euros ($1.16 billion) to a leading alternative investment firm to reduce debt. The transaction follows Adler’s sale of residential and commercial property for 1.49 billion euros to rival LEG Immobilien after an activist investor described it as “not investible”. The company disputes the investor’s report. Adler, which did not name the buyer, said the term sheet sets out the key points of the sale of 14,135 apartments and 233 commercial properties mainly located in eastern Germany, adding that the sale price is higher than the book value. The transaction, which will not have any impact on Adler’s full-year net rental income and funds from operations targets, is expected to close in the first quarter of 2022, the company said. Shares in Adler were up 3% at 0846 GMT. ($1 = 0.8593 euros) (Reporting by Zuzanna Szymanska Editing by David Goodman)