In a year when the private equity industry took a political licking, the Blackstone Group is feeling the effects of a weak deal-making climate.

The firm, headed by Stephen A. Schwarzman, reported adjusted profits of $450 million for the fourth quarter of 2011 on Thursday, down 12 percent from the same period a year ago. That beat analyst expectations of $441.7 in adjusted profits.

Blackstone reports its profits using a nonstandard metric called economic net income, which excludes charges including those related to the company’s 2007 initial public offering. On a generally accepted accounting principles basis, the firm reported a loss of $123 million in the fourth quarter, compared to an $11 million loss in the same quarter last year.

In all of 2011, Blackstone’s total assets under management jumped 30 percent, to $166.2 billion, and its profits fell slightly to $1.39 billion from $1.42 billion in 2010. On a generally accepted accounting basis, the firm reported a loss of $269 million on the year.

“Despite volatile markets and struggling economies, Blackstone had strong performance in 2011,” Mr. Schwarzman said in a statement. “Our investors view us as a critical partner, helping them protect and grow their capital.”

Many private equity firms struggled in 2011, as a weakened financial sector made buyouts harder to finance and execute, and lower performance fees hampered profitability. Blackstone’s private equity group felt particular pressure in 2011, notching $578.8 million in revenue for the year, 30 percent lower than in 2010.

With the deal-making slowdown, some of Blackstone’s lesser-known divisions have picked up some of the slack. The firm’s real-estate group had full-year revenues of $1.6 billion, up 60 percent from last year’s haul of $1 billion. But its hedge fund solutions, credit businesses and financial advisory businesses all saw their revenues decline on the year.

Blackstone could still pull off big deals in 2012. The firm’s funds had $32.9 billion in uninvested capital, known as “dry powder,” at the end of 2011. Roughly half of that capital is held by the firm’s private equity division.