Southeast Asians have the unhappiest sex lives in the world, making love less often than people elsewhere and getting the least satisfaction from it, according to a global survey.

French people have sex most frequently, at 7.7 sessions a month, while Germans and Britons had 6.45 and 6.4 sessions, respectively, according to the survey commissioned by the manufacturer of anti-impotence drug Viagra.

The survey of almost 13,000 people across 27 countries revealed the global sex frequency average to be 6.5 times a month, with 50 percent of those surveyed saying they were very satisfied with their sex lives.

Southeast Asian couples fell below the benchmark levels, with Indonesians coming closest to the global average, indulging 5.75 times a month. Singaporeans have sex 4.55 times a month and Thais 4.3 times, while people in Hong Kong averaged just 3.55 sessions, the survey found.

Indonesians were as unhappy in bed as people in Hong Kong, with only 27 percent in both places saying they were very satisfied.

Malaysians, who had sex an average of just 3.5 times per month, were the happiest in Southeast Asia, with 42 percent very satisfied with their sex lives.

Increased stress levels caused by economic prosperity and modern Asian lifestyles, including unhealthy eating and drinking habits, contributed to poorer sex performance, said Peter Lim, a senior Hong Kong urologist.

"They (executives) are all stressed out and that contributes a lot to a poorer performance in the bedroom," said Lim, an erectile dysfunction expert with a local hospital who was invited by Pfizer to comment on the survey results.

"The second reason is the pace of life, the drinking, eating, smoking has caught on," Lim said.

Urbanized Hong Kong was similar to Singapore in terms of stress affecting bedroom performance, he said.

However, in developing nations like Thailand and more relaxed areas of Asia like Penang and Malacca, men's failure to have an erection was the main reason for poorer sex performance.

Mexicans scored the highest sex satisfaction levels with 74.5 percent declaring they were very satisfied, followed by Brazil at 64.5 percent and Spain at 56.6 percent.