ZipRealty.com jumped two places to third, Yahoo Real Estate improved to second on the Hitwise top-20 list of real estate Web sites in June from May, with  and RE/MAX's remax.com sinking from second to fourth. ColdwellBanker.com dropped from 13th in May to 18th in June.

Longtime category leader Realtor.com had a 4.46 percent market share among real estate category Web sites, according to the latest Hitwise report, while ZipRealty.com had a 2.7 percent share and Yahoo's realestate.yahoo.com site had a 2.7 percent market share.

The Hitwise rankings are based on U.S. market share of visits, from a Hitwise sample of 10 million U.S. Internet users.

MSN Real Estate's realestate.msn.com Web site, which ranked 10th on the list in May and 18th in April, dropped to 15th in June with a 1.17 percent market share.

All apartment rental search sites on the top-20 list gained in the rankings from May to June.

Rent.com improved from sixth in the May rankings to fifth in June; Apartments.com moved from 11th to 10th; and ForRent.com improved from 19th in May to 17th in June.

The top-10 real estate category Web sites received 23.7 percent of all visits to that category in June, with the top-100 Web sites receiving 65.3 percent of visits. The average visit duration to real estate category Web sites was 11 minutes, 45 seconds in June -- that is up from 11 minutes, 31 seconds in May.