The head of tennis's governing body expressed disappointment on Friday as a key move to revamp the Davis Cup and Fed Cup competitions failed to win approval.
International Tennis Federation (ITF) president David Haggerty said he had concerns over the futures of the historic tournaments after the unsuccessful attempt to cut singles matches from five to three sets.
The ITF's annual general meeting in Ho Chi Minh City approved three other measures, and 63.54 percent of voters backed the move to three tiebreak sets -- just short of the two-thirds majority required.
"We respect the decision of the AGM but are disappointed that our member nations have not approved the full package of Davis Cup and Fed Cup reforms endorsed by the ITF Board," Haggerty said in a statement.
"Change is needed to ensure the long-term future of these iconic and historic competitions, and we remain committed to working with our national associations and other stakeholders on finding ways to enhance the Davis Cup and Fed Cup."
Reducing singles matches to three sets had been seen as important to make the men's and women's international team competitions more viewer-friendly in a congested sports schedule.
The 117-year-old Davis Cup and the Fed Cup, which dates from 1963, often struggle to attract the spotlight in a sport which focuses on the four Grand Slam tournaments and has busy men's and women's tours.
The ITF meeting approved a move to give Davis and Fed Cup finalists the choice of hosting their first-round ties the following year.
The availability of match and practice courts was reduced to make hosting cheaper, while Davis Cup pre-tie player commitments were cut to a single function combining the draw, media interviews and an official lunch.