Group disability insurers protected about 39 million U.S. workers against long-term disability during the first half of the year, 5% more than they protected during the first half of 2006.

The number of U.S. workers protected by group short-term disability policies also increased 5%, to more than 16 million.

JHA, Portland, Maine, published the revenue growth rates in a summary of results from a survey of 30 major U.S. disability insurers.

JHA, a disability risk management and consulting unit of General Re Life Corp., found that premium revenue from new sales was up 15% both for group LTD coverage and for group STD coverage.

New sales revenue for LTD coverage totaled $915 million, and new sales revenue for STD coverage amounted to $402 million.

Premium revenue from in-force cases rose 6% for LTD coverage, to $4.7 billion, and 8% for STD coverage, to $1.7 billion.

Average premium revenue per employee insured increased 1% in the group LTD market, to $236, and by 3% in the group STD market, to $201, according to JHA.

UnumProvident Corp., Chattanooga, Tenn., ranks first in terms of revenue from in-force group disability cases.

Unum also ranks first in terms of the number of new LTD and STD cases placed.

Hartford Life, a unit of Hartford Financial Services Group Inc., Hartford, ranks first in terms of revenue from new LTD and STD sales.