Seyfarth Shaw is laying off a substantial number of lawyers and staff members following soft demand in the first quarter.

Above the Law first reported Tuesday afternoon on the reductions, which it said involved at least 40 lawyers and staffers. They come on the heels of a strong 2016 for the Chicago-based firm, which pioneered the use of Lean Six Sigma business methods in the law. Seyfarth’s gross revenue rose 6 percent last year, to $623.5 million, while profits per partner rose 3 percent, to $1.05 million.