Blackstone has clinched a deal with GLL Real Estate Partners to buy the MesseTurm office tower, Frankfurt's second-tallest building, two sources told Reuters. The price tag was 250 million euros, one of them added.

Earlier on Tuesday, German real estate group IVG Immobilien said it had agreed to sell another Frankfurt high-rise called Pollux to Blackstone, which people familiar with the matter said was a deal worth more than 100 million euros.

Blackstone declined to comment on the MesseTurm deal, while GLL was not immediately available to comment.

Blackstone had $279 billion in assets under management at the end of June, $80 billion of which in real estate.

IVG, the co-owner of London's landmark "Gherkin" tower, earlier this year escaped insolvency when investors approved a proposed debt-for-equity swap.

(Writing Ludwig Burger; Editing by Georgina Prodhan and Mark Potter)

By Arno Schuetze and Alexander Hübner