Cassidy is no longer the king of K Street — for now.

Aided by a $1.5 million boost in lobbying revenues, Patton Boggs vaulted ahead of Cassidy & Associates as Washington’s top lobbying firm, according to a semiannual review of lobbying disclosure forms for the first half of 2003.

Cassidy, which had safely held the No. 1 spot in the rankings for years, was eclipsed by just $20,000 in the Jan. 1 to June 30 period.

Patton reported $14.33 million in revenue, compared with $14.31 million for Cassidy, sharpening the already intense rivalry between the two powerhouse firms.

Cassidy was not the only big-time firm to fall in Roll Call’s rankings, which are based on receipts from the first six months of the year.

Piper Rudnick, which last year took over lobbying giant Verner, Liipfert, Bernhard, McPherson & Hand, slid two spots to No. 6 on the list, and Barbour, Griffith & Rogers fell out of the top 10 for the first time.

Overall, K Street’s top firms continued to soar amid otherwise sour economic times and meager job growth nationwide.

The top 10 firms hauled in $105.34 million for the first half of the year — the first time the group topped $100 million in booking for a six-month period.

The midyear total was a 19 percent jump from the first half of 2002 and a 27 percent bounce from the same period in 2001, according to disclosure filings.

One of the most notable performances of the period came from Greenberg Traurig, which posted $13.5 million in revenue, enough to claim the No. 3 spot in the lobbying rankings for the first time.

Akin Gump Strauss Hauer & Feld held steady in the fourth slot with $13.1 million in lobbying revenues, while Van Scoyoc & Associates moved up a position to No. 5.

Rounding out the top 10 were No. 6 Piper Rudnick ($9.2 million), No. 7 Williams & Jensen ($8.8 million), No. 8 Hogan & Hartson ($7.4 million), No. 9 Washington Council Ernst & Young ($6.6 million) and No. 10 Quinn Gillespie & Associates ($6.5 million).

The figures only include fees for lobbying Congress or the administration, which are required to be reported every six months by the 1995 Lobbying Disclosure Act.

The totals do not include revenues from lobbying state officials, conducting public relations campaigns or pitching contracts to federal agencies.

That could explain Cassidy’s slight slip. The firm has recently been focusing some of its efforts on landing federal contracts from the Homeland Security Department. Income from such federal marketing work is not included in the disclosure forms.

“We have switched a lot of our efforts to federal marketing,” Gerald Cassidy, the firm’s chairman, told Roll Call earlier this year. “A good deal of our growth is in that area and we expect a good deal of our future growth to be in that area.”

Until this year, the foursome of Cassidy, Patton Boggs, Akin Gump and Piper Rudnick had a lock on the top slots in the rankings.

But the fall of Piper Rudnick and Barbour Griffith — and the rise of Greenberg Traurig — marks an interesting shift in K Street’s hierarchy.

Piper Rudnick dropped in the rankings after bringing in less lobbying revenue in the first half of this year than it had in the previous two years.

The $9.2 million in lobbying fees for the six-month period was nearly $2 million less than the total the firm reported for the previous six months.

Barbour, Griffith & Rogers was overcome by a wave of firms as it failed to increase revenues as fast as its rivals without rainmaker Haley Barbour, who is running for governor of Mississippi.

Quinn Gillespie & Associates, in contrast, dipped into the top 10 for the first time by boosting revenue by one-third to $6.5 million for the period.

But, like Barbour, Griffith & Rogers, the firm may have trouble maintaining that pace without partner Ed Gillespie, who gave up day-to-day control this spring to become chairman of the Republican National Committee.

Meanwhile, Greenberg Traurig continues its rapid ascent up the lobbying charts.

By hauling in $13.5 million in revenue for the period, the Republican-dominated firm climbed to its highest ranking since GOP insider Jack Abramoff split off from Preston Gates a few years ago.

“We have finally really started expanding the practice,” Abramoff said.

Jessica L. Brady and Inga Beyer contributed to this report.