Baker Botts enjoyed a record year in 2016, with revenue up 20.2% on 2015 and profits per partner up 36.6%, boosted by some big contingency fees and strategic investments.

The bottom-line numbers were rosy – gross revenue hit $846.5m (£674m) for 2016, compared with $704.5m (£561m) in 2015, while net income reached $435m (£346m), up from $301m (£240m) the prior year.

Profits per partner were $2.465m (£1.963m) in 2016, up from $1.805m (£1.438m) in 2015, and revenue per lawyer came in at $1.195m (£952,000) in 2016, up 18.3% from $1.01m (£805,000).

"We've been working really hard on our business plan. We've invested heavily in all of the things that make practices hum," said managing partner Andrew Baker. He added that the firm has invested in lawyers, IT, professional development, marketing, pricing training, and project and practice management.

In 2016, the firm focused on the energy and technology sectors, and while it is known for its longstanding energy practice, the number of clients in the firm's energy sector is about equal to the number of technology clients, Baker said. He noted that the firm added intellectual property lawyers in 2016 and expanded in the Silicon Valley, with the office it opened in San Francisco in January 2016.

The firm also beefed up other practices, including antitrust, white-collar defence and bankruptcy, he said, and added lawyers in London, including energy transactions partner Paul Exley from Jones Day and London construction partner Stuart Jordan from King & Wood Mallesons.

Baker said the firm's earnings have trended upward for the last four years, but this year benefited from contingency fee litigation. He declined to say how much the firm made from those lawsuits in 2016, but said the windfall came from more than one case and "contributed strongly" to the firm's bottom line. (Multiple outlets reported last year that the firm earned a significant fee related to a $755m (£600m) Vivendi settlement with Liberty Media.)

He said the flush times were reflected in 2016 bonus pay. "When we had these measures of contingent success… there's not an employee of the firm who did not participate," he said.

The firm had 708 lawyers on a full-time equivalent basis last year, up 1.3% from 699 in 2015. There were 278 equity partners in 2016, one more than in 2015.

Baker Botts prepaid 2017 expenses in late 2016, Baker said. Because the firm has had four good years in a row, it has steadily increased prepays to give the firm "cushion and flexibility", he said.

Baker said the energy practice was challenging early in 2016 but improved as the year went on. So far this year, the energy business is "really picking up", he said.

In the US, Baker Botts has offices in Austin, Dallas and Houston in Texas, as well as New York, Palo Alto, San Francisco and Washington, DC. Elsewhere, the firm has bases in Beijing, Brussels, Dubai, Hong Kong, London, Moscow and Riyadh.

Baker added: "Contrary to others, we doubled down in Moscow – we added some really significant arbitration resources, hiring Ivan Marisin and Vasily Kuznetsov from Quinn Emanuel Urquhart & Sullivan. We feel like we need to invest in our platform – Europe, and particularly London, are very much a part of that.

"Brussels has also been a key part of our global competition practice. It is a very important part of the firm and participated fully in producing the kind of results we are glad we had this year."