The aim of this study is to examine how knowledge-intensive services firms sustain relationships with their clients in competitive international business environment and propose a framework of customer-relationship management strategy aligned with the entrepreneurial orientation of the firms under consideration. Developing, enhancing and sustaining relationships with customers has been one of the key areas of research in marketing, not least within knowledge-intensive service industries (Kalwani and Narayandas, 1995; Das and Rangan, 2004). Research has shown that retaining customers is a less expensive and less time-consuming process than attracting new customers (Rosenberg and Czepiel, 1984). Furthermore, building intimate relationships with customers is crucial for creating new knowledge, customer loyalty and increasing profitability (Mattila, 2001). Yet, the relationship between customers and service providers is a complex process. Significant efforts have been made by researchers to uncover the dynamics of the relationship, such as probing into such questions as explaining the types and levels of relationship, factors that determine the quality of a relationship, and the service quality and its effects on the relationships (Ruyter, Moorman, and Lemmink, 2001). Of crucial importance for understanding customer relationship is strategies firms deploy in building long-term relationships with customers in international markets (Salter, 2001; Narver et al., 2004; Kocak, and Abimbola, 2009). Furthermore, having customers involved in the production of the service as co-producers (Vargo and Lusch, 2006) creates a special relationship between customers and employees. However, what happens to the relationship when customer requirements changes due the changes in competition or technology. This question is important as little is known about how, in the face of disruptive technological changes and fierce market competition, firms can maintain strong relationships with their clients in international markets. The continuous changes in the technological and competitive landscape are making it harder for service firms to keep their customers satisfied and commend their commitment for long periods of time (Narver et al., 2004). Theoretical background: B2B customer relationship marketing literature (Jaworski and Kohili, 1993; Salter, 2001; Narver et al., 2004) dwells on the benefits of developing long-term partnerships, trust, commitment, and satisfaction, which are the parameters of relationship quality and long-term orientation in customer relationship (Macintosh, 2007; Skarmeas et al., 2008). Customer relationship is a key aspect of the competitive sustenance of knowledge-intensive service firms in international markets, yet, this has not received much attention in the literature. Customer relationships are unique, develop over time and may serve as a resource which will be difficult for competitors to imitate or purchase (Dyer and Singh, 1998). Such resources can be source of competitive advantage in international market (see Barney, 1991) particularly when the service firm is new to the market. To overcome the challenges of newness and foreignness firms need to build a level of cooperation, trust, and long-term relationship with the customers that reveal the quality of relationship (Lahiri and Kedia, 2011). In the context of business-to-business relationships, relationship quality has been suggested to be the binding factor between partnering firms, such that their relationship goes beyond mere exchange of goods, services, or capital. The resulting benefits would then include customer satisfaction, enhanced perception of fairness and justice, customer loyalty, relationship satisfaction, positive word-of-mouth publicity, repeat transactions, and business continuity (Wu et al., 2006; Kale and Singh, 2009). Unlike in the previous studies where the concern is mainly about sustaining ongoing relationships with the customers through understanding and meeting the current requirements, this study stress on anticipating and shaping customers’ future needs, and proactively investing in those relationships, accordingly.Building on these initial theoretical considerations, this paper suggests three important strategies that explain why knowledge-intensive firms in international markets can endure over time after their initial phase of internationalisation. These are: customer relationship quality management (Jaychandran et al., 2005; Payne and Frow, 2005; Kim et al., 2011); customer relationship proactiveness (Sharma, 1994; Slater and Narver, 1998; Johannessen et al., 1999); and customer-focused innovativeness (Lumpkin and Dess, 1996; Zahra et al., 2000). Research design/methodology – Following Yin (1994), a multiple case studies approach is used. We draw on case study material gleaned from four Indian knowledge-intensive service firms, two are old firms, being in existence for more than 20 years, and two new firms, which we consider as "particularly revelatory" cases (Eisenhardt & Graebner, 2007: 27), because the old firms have sustained long term relationships with their clients in international market and new ones are trying to develop such relationships (Nasscom, 2010). Data was collected through personal interviews and from company websites and it was analysed abductively.Findings: The findings suggest that it is the entrepreneurial orientation (Lumpkin and Dess, 1996- innovativeness, proactivness, and risk-taking) of knowledge-intensive B2B firms in combination with other capabilities, such as marketing capability, service delivery capability, that explains their continued relationship with clients in international markets. Entrepreneurial orientation focuses on knowing the customers’ present and latent needs so as to cater for them in a proactive, innovative and unique way. Their focus on knowing the customer intimately helps the firms to lock in their customers and to retain them over long periods of time, thereby insuring their sustenance and continued development. Findings reveal that customers also play an active role in developing the intimate relationships and the transfer of intimate knowledge. This is mainly because of the high cost associated with the replacement of the knowledge that the partners have developed of each other and the mutual trust and commitment the partners invest in. Customers understand the risk and cost associate with the replacement of provider and, thus, are careful in the selection of service providers. The relationship normally begins with small projects that do not have serious cost and risk implications. As the relationship solidifies, and as each party learns more about the other party’s systems and processes, trust between the partners increases. Trust between top managers as well as between people on an operative level are equally important, thereby making relationship-building the responsibility and concern of everybody in the company. The intimate knowledge of the customer provides ample opportunity to the service firms to develop the required capabilities for meeting current and future needs of the customers. To the extent that the relationship is a long-term commitment, the cases under consideration witness how, in order to retain clients, they have to proactively anticipate their clients’ needs, as these are always changing. Being proactive helps the firm to keep abreast of their clients’ business thrust. Furthermore, firm has to be innovation-driven, and on the lookout for new technological trends. Leveraging its unique knowledge of its customers, these firms are more able than competitors to identify what future solutions would be relevant to the businesses of the clients. Both sensing and scanning the environment, on the one hand, and watching the customer’s evolving requirements, on the other. In summary, earlier studies have indicated that intimate knowledge of customers and good relationship are critical to market success, but have failed to how such intimacy can be developed and sustained over a period of time. The findings of this study provide insights into the factors underlying customer intimacy, such as customer relationship quality, a proactive approach, and the pursuit of innovativeness. In this sense, the current study fills an important gap in the literature on knowledge-intensive services. The study also has practical relevance relating to firms and managers operating in an knowledge-intensive industry.