The steady drumbeat of layoffs in the legal world continued yesterday with the announcement by Reed Smith L.L.P. that it would let go 100 lawyers and staff in offices in the United States and London.

The firm, which is headquartered in Pittsburgh and has a large Center City office, said it would let go 17 lawyers in various U.S. offices and nine in its London office. A total of 74 administrative staff also would be laid off, the firm said, in the United States and the United Kingdom.

"While most of our practices are performing well so far in 2009, our capacity has continued to materially exceed demand in certain parts of our transactional practice," the firm said. "Unfortunately, we do not foresee significant changes in this picture in the near or medium term."

In December, the firm announced that it had cut about 115 administrative staff to cope with the falloff in legal work. Until yesterday, it had laid off no lawyers.

It has become increasingly apparent that few, if any, very large firms are immune from the wave of downsizing sweeping through the industry. The very diversity in practice areas that caused revenue to boom just a few years ago now is exposing some of the largest firms to the downturn.

Even so, the cuts at Reed Smith this time around appeared relatively modest. The firm said it had let go 4 percent of its associates, or non-partner lawyers, and 5 percent of its administrative staff.

Reed Smith's leaders had said earlier that they were counting on their extensive network of overseas offices to insulate them from the sharp falloff in business in the United States. For a time it did, but now the downturn has had a deep impact on overseas markets as well.

The firm said that the laid-off lawyers worked in "the corporate and real estate areas of our practice, where demand continues to be slow."

The news yesterday came amid substantial turmoil in the legal market.

On March 23, one of Philadelphia's most venerable old-line law firms, Wolf, Block, Schorr and Solis-Cohen L.L.P., said it would dissolve in the coming months as a consequence of the flagging economy, partner defections, and a decision by its lender to tighten the terms of its lending to the firm.

Then, on Thursday, Dechert L.L.P, a firm headquartered in Center City with more than 900 lawyers in the United States and abroad, said it was laying off 63 lawyers and 62 administrative staff in offices in the United States and overseas.

Other large Philadelphia firms have had layoffs, too, including Morgan Lewis & Bockius L.L.P. and Blank Rome L.L.P.

In addition, firms have delayed the start of their incoming classes of lawyers by a year, in some instances providing stipends for their new lawyers of several thousand dollars a month provided they go to work for a public-interest organization.

That has been a boon to organizations such as the Senior Law Center of Philadelphia, which provides legal services to low-income seniors who are subject to financial exploitation and other problems and is swamped with requests for help.