LONDON (AP) _ Manufacturers of infant formula are routinely violating an international code which opposes distribution of free samples and promotes breast milk as best for babies, according to a survey published Saturday.

The British Medical Journal, which published the survey, called in an editorial for all governments to incorporate a World Health Organization code into law and insisted all manufacturers abide by the provisions.

``The frequency of the violations ... shows that 16 years after the World Health Assembly adopted the code, its requirements are still unmet,'' research coordinator Anna Taylor said.

The Paris-based International Association of Infant Food Manufacturers could not be reached for comment Saturday.

The 1981 WHO code mandates that all infant formula promotions inform mothers that breast feeding is their best option. It also bans free samples, except for professional research, and forbids inducements to health workers who might then promote a particular product.

It is up to individual countries to give the code the force of law.

The WHO estimates that 1.5 million deaths a year could be prevented by effective breast feeding.

The survey _ sponsored by the British office of the U.N. Children's Fund and 27 British charities, churches and other organizations _ quantified the level of violations in four cities.

Researchers interviewed 3,050 women and 466 health professionals at 165 health facilities in the cities in Bangladesh, Poland, South Africa and Thailand. They found 21 companies were giving away samples of breast milk substitutes.

In Bangkok, Thailand, for example, where compliance with the code is voluntary, 97 of 370 mothers reported receiving free samples of a breast milk substitute, a feeding bottle or a nipple. That compared with 1 of 385 mothers in Dhaka, Bangladesh, where compliance with the code is required by law.

In Warsaw, Poland, where there is no law, 56 percent of health facilities surveyed received information from formula manufacturers or distributors which violated the code, including literature that promoted their products as being better than breast milk. And 18 percent of Warsaw health workers reported receiving gifts from manufacturers, such as pens and notebooks.