Mergers and acquisitions among the world's top agents and brokers made room for new companies in the ranking of the 1996 Top 100 brokers of U.S. business, as overall growth in revenues continued-but at a slower pace from the previous year.

The gross revenues generated from U.S. clients by the Top 100 brokers of U.S. business increased by 7.3% to $10.3 billion from $9.6 billion in 1995. That is only about half of last year's gross revenue gain of nearly 14% by the Top 100 brokers (BI, July 22, 1996).

Estimated 1996 revenues from the top 20 U.S. retail brokerages increased an impressive 47.2% to $5 billion from $3.39 billion.

The amount of estimated U.S. revenues necessary to make the ranking of the 100 largest brokers of U.S. business climbed only 4.3% to $10.1 million.

First Chicago NBD Insurance Services made the most significant climb on this year's Top 100 chart-to No. 13 from No. 42. First Chicago NBD's leap reflects a more precise accounting this year of the revenues First Chicago brought to its merger with NBD in late 1995.

Significant growth also was reflected in the leaps made by Procter Homer Warren Inc. to No. 49 from No. 74 after acquiring Western Flood in Thousand Oaks, Calif.; No. 19 Alburger Basso de Grosz Insurance Services Inc. from No. 30 after acquiring Metzger & Wilkey in Petaluma, Calif., and Willis Corroon in Sacramento, Calif.; and No. 62 Berwanger Overmyer Associates from No. 77 after acquiring Turner & Shepard Inc. in Columbus, Ohio.

Riedman Insurance was the most prominent of the 14 newcomers to the chart, entering at No. 22, with 1996 U.S. revenues of $41.4 million. If Riedman had submitted a form last year, it would have ranked No. 24.

BB&T Insurance Services Inc. joined the chart at No. 30 with revenues of $32.4 million. BB&T's four acquisitions in 1996 accounted for its growth from 1995 revenues of $16.9 million, which would have put it at No. 50 had it submitted a form last year.

Another company that would have made last year's chart-at No. 69-if it had submitted a form is No. 55 InterWest Insurance Services Inc.

Wm. Rigg Cos. joined the ranking at No. 39. Riggs would have been No. 45 in the 1996 chart had last year's questionnaire been submitted without errors in reported gross revenue.

Posse Walsh Buckman Van Buren Inc. broke into the Top 100 this year at No. 98.

Commerce National Insurance Services Inc., a company formed in 1996 through the merger of Buckelew & Associates, Chelsey & Cline, Keystone National Cos. Inc. and The Morrissey Agency, joined this year's ranking at No. 58.

Acquisitions and internal revenue increases pushed these companies into the rankings: Summit Global Partners Inc., No. 46; Allied American Agency Inc., No. 64; Van Meter Insurance, No. 86; Wharton/Lyon & Lyon, No. 87; Davis Baldwin Inc., No. 88; and Conseco Risk Management Inc., No. 96.

Of course, several big names-Johnson & Higgins, Alexander & Alexander Services Inc., Minet Group, Bain Hogg Henderson & Phillips Insurance and CECAR-dropped off the chart after being acquired.

The Pilgrim Organization, Anchor Pacific Underwriters Inc., and Bolton/RGV Insurance Brokers were noticeably absent as a result of their rivals' growth.

Ranked No. 47 last year, the Lawrence Agency Corp. falls from the chart after filing for bankruptcy earlier this year, while Gow & Hanna Inc. and Capax Management Insurance Services, which previously ranked Nos. 78 and 96 respectively, did not complete questionnaires this year.

Saldana & Associates Inc. mistakenly was ranked No. 53 last year due to an error on their questionnaire and did not make the Top 100 this year.

Several networks of individually owned companies are not included in the rankings.

The 57 members of Assurex International combined made $507 million in 1996 revenues, which would have made the Columbus, Ohio-based agency network No. 5 in the world.

And if the 60 franchises in independent agency franchise organization ISU Corp. could combine their 1996 revenues, the total would be $135.5 million, which would make the group the ninth-largest retail broker.

The 14-member UNISON network is in discussions regarding its future after Johnson & Higgins, its largest member, was acquired by Marsh & McLennan Cos. Inc. earlier this year. In 1995, UNISON had a combined $1.7 billion in revenues. 1996 revenues are unavailable, according to a spokesman.

Fifteen brokers slipped lower in the chart this year despite increasing their U.S. revenues. Dann Brothers Inc. witnessed a 9.8% increase in U.S. revenues from 1995 and still fell one notch to No. 76.

Ten brokers reported declines in retail brokerage revenues, resulting in a drop in ranking from the 1996 chart. Among them were Hastings-Tapley Insurance Agency Inc., down 7.9%, and MLW Services Inc., down 6.4%.

The Cal-Surance Cos. had the most significant drop in ranking: 20 spots to No. 69 after a 25.6% decline in U.S. revenue to $12.8 million. The decrease was attributed to an internal change in accounting for company units. Anco Insurance Managers Inc. had the next biggest drop: 14 spots to No. 77 as a result of the spinoff and sale of several books of business.

Sally Roberts contributed to this story