Aug 20 (Reuters) - Wall street investors Boaz Weinstein, Bill Ackman and Marc Lasry have made a rival offer for hedge fund firm Sculptor Capital Management, the Wall Street Journal reported on Sunday.

Asset manager Rithm Capital last month agreed to acquire Sculptor for $639 million.

Weinstein’s group presented an offer for Sculptor that was rejected during the sales process and it has subsequently increased its bid to more than $12 a share, people familiar with the matter told the Journal.

(Reporting by Kanjyik Ghosh in Bengaluru; Editing by Muralikumar Anantharaman)