Jenner & Block recorded a remarkable jump in revenue and profits in 2014, continuing the wild swings of the firm’s fortunes in recent years. The improved results were in part due to its work for General Motors Corp. investigating the carmaker’s ignition switch problem, which was led by chairman Anton Valukas.

Gross revenue rose 14.1 percent, to $408 million, and revenue per lawyer increased 23 percent, to $1.015 million. Profits per partner soared 30.8 percent, from $1.235 million to $1.615 million.