The total number of Web sites on the Internet is contracting as domains registered during the Internet boom of late 1999 are dropped, according to Web-server information firm Netcraft.

Netcraft's Web Server Survey found that the number of Web sites fell by 182,142 from November to December last year. In November, 36,458,394 Web sites were found, dropping to 36,276,252 in December. The decline is only the second recorded by the survey, which started in August 1995.

The first drop was a blip caused by failures and changes at several large hosting companies, Netcraft said. This time, however, the number of domains not renewed exceeds the number of new registrations, resulting in fewer Web sites. The number of .com domains fell by about 130,000 in the last quarter of 2001, Netcraft claims.

Domains are typically registered for two-year periods. Web addresses claimed in late 1999, a period described by Netcraft as one of rampant domain-name speculation, are coming up for renewal. Keeping a domain such as .com, .net, or .org for two years costs c.$70 at most registrars.

Many more domains will be coming up for renewal in the coming months, as domain-name speculation accelerated in early 2000, Netcraft said. The drop in domains on the Internet could be offset by the recent introduction of new top-level domains (TLDs) such as .biz and .info, according to Netcraft.