This thesis reports an ethnographic study of the social meanings underlying code and style choice in the situated discourse of two business organisations in Malaysia. It explains choice in these contexts against the broader contextual backdrop of English as the traditional normative code of Malaysian business, and Malay as the national language and linqua franca. The language of seminar presentations and training sessions, selected as a type of formal speech event in such contexts, was analysed to determine if the norms governing English are in place and how they are interpreted in these contexts. An integrated theoretical framework, comprising an ethnography of communication with elements drawn from Accommodation Theory and the Markedness Model of code-switching, was employed to explain institutional and individual choices. In explaining choice, the study provides a contextualised model of the varietal range and stylistic continuum of Malaysian English (ME) based on the ethnographic evidence. It reveals that ME is the unmarked choice in Malaysian business, rather than approximations to exonormative models, such as Standard British or General American English. These varieties of standard English were, in fact, marked choices, although the formality of the workplace settings might have predicted otherwise. Neither was there consistent adherence to standard English usage, despite the use of register, nor clearly defined functional norms of spoken English. Instead, variability in speech forms was clearly demonstrated and three types or variants of ME were evident. A subvariety which was identified as Educated Malaysian English (EME) was oriented to as the educated speech norm. But far more evident was a norm of communicativeness' which was alluded to as a point of reference, by informants in the interview data. Another subvariety, identified as Colloquial Malaysian English (CME), was the familiar and solidarity code while the last subvariety identified was a pidgin or broken' English. ME was spoken in ethnically distinct ways, mainly in the prosody of the native languages of the speakers, as ethnolects. Malay, was a marked code and the marked choice despite being the national language and linqua franca. However, Malay was marked only in relation to tacit organisational policy and its use was not proscribed. But its use was not encouraged either. The study demonstrated that style shifting along the full varietal range of ME, the use of a seamless mixed code and code-switching into Malay, were more common ways of speaking in these settings than the use of normatively prescribed patterns. This challenges generally held notions and expectations regarding the use of English in Malaysian business settings. Such choices are explained as locally motivated pragmatic selections within the specific contexts of the workplace settings and in relation to the larger context of the Malaysian sociolinguistic situation.