If you were among law firm associates or legal staffers who still had a job by the end of Thursday, consider yourself lucky.

Six prominent firms sent packing more than 700 attorneys and legal staffers, in what may well become known as Black Thursday in the legal industry. DLA Piper; Holland & Knight; Goodwin Procter; Bryan Cave; Epstein Becker & Green; and Dechert all confirmed layoffs on Thursday, adding to what has become a brutal contraction of legal jobs. Faegre & Benson also confirmed on Thursday that it initiated layoffs on Wednesday, while Cozen O’Connor confirmed that it let go of staffers on Tuesday.

The international law firm DLA Piper on Thursday cut 80 associates and 100 staffers from its network of U.S. offices. Thursday’s cuts were in addition to the firm’s move earlier in the week to eliminate 30 attorneys and 110 staff positions in its U.K. offices.

The majority of the laid-off associates were in the corporate finance and real estate practices, said Francis B. Burch Jr., chairman of the 3,800-attorney firm’s global board. The downsizing affected the New York office the most, where the firm trimmed 16 associates. It also laid off 12 associates in Chicago. The other reductions were primarily on the West Coast. DLA Piper has about 1,370 attorneys in the United States. Burch cited “prudent business management” as the reason for the reductions. “We need to be the right size going forward,” he said. The associates laid off had varying degrees of experience, Burch said.

Holland & Knight’s layoffs also were significant. The law firm announced a “restructuring” on Thursday, which included getting rid of 70 lawyers and 173 support staffers across the firm’s 21 offices.

The Boston area is feeling the pain of job cuts. Goodwin Procter said it laid off 38 associates and 36 staffers on Thursday, which equates to a 4% reduction in associates and staff. Associates and other categories of attorneys not on the partnership track were among those let go, as were paralegals, secretaries and administrative staff, according to the firm. The business law practice was most affected by the cuts, which were concentrated in the firm’s New York and Boston offices. However, the firm said all of its offices will feel the impact of the reductions.

Like the other firms, Goodwin Procter pegged the cuts to the economy. “While Goodwin Procter is fundamentally strong and healthy, we — like most law firms — are not immune to the effects of this recession,” reads a statement from the firm. “Our transactional practices, in particular, have seen a decline in demand for legal services that unfortunately does not show signs of improving in the near term.”

The statements said that the uncertain length of the downturn was a factor in its decision to eliminate jobs.

Thursday’s layoffs weren’t entirely concentrated on the East Coast. Bryan Cave, which has its largest office in St. Louis, laid off 58 attorneys and 76 staffers. A firmwide memo from chairman Don Lents said that the reductions represent about 5% of the firm’s associates, and 6% of its legal staff. The memo did not specify what offices or practice areas are affected by the cuts.

Lents also announced that the firm would not raise salaries in 2009. In November, Bryan Cave said it would delay any decision on associate and staff raises for three months in order to evaluate the economy.

“Over the course of the past year, we implemented a number of measures to reduce our costs,” Lents wrote in his memo. “Unfortunately, the economy has continued to deteriorate, and we have concluded that further steps are necessary to adapt to this business climate.” In November, Bryan Cave merged with Atlanta-based Powell Goldstein.

Epstein Becker & Green laid off 23 attorneys and 30 staff members across the firm. A statement from the firm cited the economy as the reason for the reduction, but it said it is on “solid financial footing,” and that no further layoffs are planned.

“This decision was an extremely difficult one, and was made only after very careful consideration of our options,” the statement reads. A spokesman declined to specify the offices or practice areas most affected by the cuts.

Dechert also confirmed that on Thursday it let go of associates and counsel, which is the firm’s classification for attorneys between the associate and partner levels.

“The firm is laying off 19 lawyers in the United States, primarily due to a reduction in client demand that has affected most, if not all, of the legal industry,” a firm spokeswoman said Thursday. She said the cuts were spread across the firm’s 11 U.S. offices and affected several practice areas. She declined to specify which practice areas were hit hardest.

This is not the first time Dechert has trimmed its head count. In December, the firm laid off 72 staffers in the United States and 15 staffers in the United Kingdom. It also laid off 13 attorneys in March 2008.

Minneapolis-based Faegre & Benson beat the layoff wave by one day, and informed 29 attorneys on Wednesday that they were being let go. It also offered buyouts to certain staffers, according to a statement from firm Chairman Tom Morgan. He said the move was motivated by the economy. “Like many firms across the country, we are aligning our resources with the anticipated demand for our services and are doing so in a thoughtful and measured manner,” Morgan wrote. “Yesterday, we announced that in the coming months we will be reducing our number of lawyers by 29. We have now met with each of those lawyers.”

Staffers were the targets of cuts on Tuesday at Philadelphia-based Cozen O’Connor, said president and Chief Executive Officer Thomas Decker. He said the firm laid off 61 administrative staff and paralegals in an attempt to “rightsize the firm.” “Our staff-to-lawyer ratio was way out of whack,” Decker said. “We had less than two lawyers to one administrative staff person, which I don’t think you will find at many other firms.”

Decker said 2008 was the firm’s second-best year ever, and that there are no plans for associate layoffs.

Already this month, Nixon Peabody; McDermott Will & Emery; Clifford Chance; and Linklaters laid off attorneys and staff.

Associate Editor Leigh Jones contributed reporting for this story.