By Ann Williams and Gabriel Chen

SingTel is raiding its war chest to boost its stake in its biggest overseas associate, Bharti Airtel.

The latter is India's largest mobile phone service provider.

SingTel said in a statement to the stock exchange late last Friday that the acquisition, which could cost up to US$641 million (S$898 million), was in line with its strategic focus on 'maximising the value of its existing businesses'.

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