TOKYO, August 9 (Reuters) – Japan's top wireless operator NTT DoCoMo Inc. is interested in buying Luxembourg-based telecom operator Millicom's Cambodian network to boost its presence in Southeast Asia, an executive said.

Cash-rich DoCoMo, which controls half of Japan's mobile market, is hungry for acquisitions in other parts of Asia as growth slows in markets at home, in the US and in Europe.

But DoCoMo has not decided to make a bid for Mobitel, which sources have priced at several hundred million dollars, and will consider other M&A targets in Cambodia and political and economic risks, said Toshinari Kunieda, senior vice president and managing director of DoCoMo's global business.

''It's like a marriage proposal – you don't make an offer the day after falling in love at first sight, you look at other potential partners, too,'' Kunieda told Reuters in an interview on Friday. ''But we will date.''

DoCoMo is also hunting for investment targets in Vietnam, Indonesia, Thailand, and China, as well as in the Middle East, Oceania and Sri Lanka, as it chases a mid-term target of boosting overseas revenues to 10 percent of its total sales in four to five years.

Based on its sales in the year ended in March, that would mean quadrupling its overseas revenues of 100 billion yen ($1.1 billion), of which about 60 percent now comes from roaming fees.

''It can't be done without M&A,'' Kunieda said. ''We will have to hunt for a majority stake somewhere.''

DoCoMo's recent foreign investments include a 26 percent stake in Tata Teleservices, India's sixth-largest mobile operator, a 30 percent stake in telecom operator Axiata's Bangladesh unit, and a 16.5 percent stake in Malaysian operator U-Mobile.

DoCoMo's shares closed up 1.2 percent, while those of No. 2 Japanese carrier KDDI Corp rose 0.2 percent and third-ranked Softbank Corp. fell 0.9 percent.