Last December, Wachtell, Lipton, Rosen & Katz advised the two buyers in a deal to take Harrah’s Entertainment Inc. private. If the $28 billion cash-and-debt deal goes through as planned, it would be the third-biggest private equity deal of 2006.

Wachtell is no stranger to leveraged buyouts, but until recently the firm primarily focused on more public-company M&A work. No longer. Wachtell advised on seven private equity deals worth more than $69 billion in 2006, fourth-best among law firms, according to Mergermarket Limited’s North American private equity deals-by-value rankings.