WASHINGTON (Reuters) - Thinking about paying someone to remodel your kitchen? You may want to reconsider. Home improvement contractors received the largest number of complaints from consumers in 1999, according to two watchdog groups that on Tuesday released their annual list of the top 10 recipients of consumer gripes.

``With alarming frequency, there are many home improvement projects that are paid for that never happen or that consumers wish never happened,'' National Association of Consumer Agency Administrators executive director Wendy Weinberg said.

Car dealers dropped to second place in the complaint survey after holding the No. 1 spot for two straight years. Household goods firms -- which include stores that sell expensive items such as refrigerators, computers and furniture -- climbed to No. 3 after coming in fourth place in 1998 and fifth in 1997.

Home improvement contractors made the No. 1 spot for the first time in the report's nine-year history, according to the NACAA and the Consumer Federation of America.

Consumers complained that home improvement contractors did shoddy work, started projects they never finished or in some cases required deposits for supplies and then never came back.

In Pinellas County, Florida, 16 people complained about a man who posed as a marine contractor specializing in seawall, dock and deck construction. One person claimed being defrauded out of $3,400 and a widow blamed her husband's heart attack on the stress from dealing with the contractor.

The consumer groups advised individuals to check out a contractor -- including contacting references, looking up licenses and checking for complaints with the local Better Business Bureau -- before handing over any money.

``The rule of thumb in business is you have to know who you are doing business with,'' Weinberg said.

Although they did not make the top 10 list, complaints against Internet firms rose a whopping 146 percent last year, the largest percentage increase for any group. The rise was led by a surge in gripes about merchandise ordered through online auctions, said the report, based on a survey of 49 city, county and state consumer agencies.

Auto repair shops dropped to fourth place in the survey, marking the first time they have not received enough complaints to make one of the top three slots. Other groups making the top 10 list included credit and lending institutions, utilities, mail order companies, collection agencies, landlords and travel and leisure firms.