BESIDES the normal beeping, there is also a brand-new buzz in the office of ABC Communications. With the announcement that the United States had lifted its longstanding embargo on Vietnam, phones immediately started ringing off the hook at the country's premier paging service. Deputy managing director, Patricia Yeung, who is based in Hong Kong, welcomed the decision saying it would be a shot in the arm for Vietnam's economy. However, she said ABC's bullish plans for the country were already on track long before the US action. After scouting Vietnam for several years, ABC Communications signed its first contract with Ho Chi Minh Post and Telecommunications in March last year, to provide a paging service to the Vietnamese city and surrounding countryside. The Hong Kong firm followed its landmark paging pact by signing a second contract last summer that effectively made it Vietnam's national paging service. The contract is not exclusive, but covers the entire country. Within four months of launching the service in Ho Chi Minh City, ABC already has 1,300 customers, Ms Yeung says. ''We expect to have 5,000 to 6,000 by the end of the year.'' Customers are also signing up for the service in Hanoi and Haiphong, where the service will be launched officially on February 19. ABC expects to extend the service soon to the Mekong Delta and central Vietnam. Its year-end goal is 10,000 customers. ''The potential is immense,'' Ms Yeung said, noting that although official statistics listed a low per capita income for Vietnamese, there was a lot of hidden wealth. ''We've been very surprised by the reaction. Some people are signing up and paying for a full year, rather than monthly.'' The ABC executive says the company will invest $10 million in its Vietnamese paging network, which should be complete by April. She says the venture could become profitable within the second year. ABC did its homework carefully before leaping into Vietnam, she said. Market surveys identified the best areas of potential growth, such as the Mekong delta and central regions of the country, where factory expansion should bring demand for a paging service. For Vietnam, a country with a poor telephone service, ABC has chosen a pager which displays text. ''The system won't displace phones, but it needn't rely upon them,'' said Ms Yeung, who made nearly two dozen visits to Vietnam in the past two years. ''Every time we go, we find something different. The improvement is remarkable.'' Firms from Singapore, Taiwan and Hong Kong have been active in Vietnam for years. ''But really, the key is good planning, hard work and having a long-term strategy. If one intends to make a quick buck, they might be disappointed in Vietnam.''