Just four months after jumping ship at UBS ( UBS), rainmaker Ken Moelis is taking the M&A business by storm. His Los Angeles-based Moelis & Co. kicked off the second half of the year in style this month by landing a role in one of the hotel industry's biggest buyouts ever. The firm advised Hilton Hotels ( HLT) in its $26 billion acquisition by Blackstone ( BX). Moelis has been hammering out the blockbuster hotel transaction for months. The deal started taking shape when he was still with UBS, but engagement letters he signed with Hilton allow him to get credit for his work on the transaction. "Ken Moelis is the consummate banker," says Jonathan Gray, co-head of Blackstone's real estate division. "He understands that transactions are about more than just numbers," Gray adds. He declined to discuss specifics about pending transactions. Indeed, it's Moelis' relationship with Hilton CEO Stephen Bollenbach that played a key part in getting the Blackstone deal done. The pair have known each other for decades. Bollenbach declined to comment on his relationship with Moelis, via a spokeswoman at the hotel company's Beverly Hills, Calif., headquarters. Known for his formidable Rolodex, Moelis left UBS after working there for seven years, reportedly because he was unhappy with the big Swiss financial institution's direction. Sources who have spoken to Moelis tell TheStreet.com that the veteran banker left UBS in part because he believes investment banks in general lack direction and create too many conflicts of interest for their clients.