BENGALURU, March 10 -- Sonata Software Ltd has filed an involuntary bankruptcy petition in a US court against a retail client over unpaid dues of about $10.65 million, an amount equivalent to roughly 6.6% of the company's incremental revenue last fiscal.

The claim highlights the financial exposure from a client ramp-down in Sonata's retail segment, which contributes about $100 million, or 8% of the company's revenue, and comes as the firm is also grappling with a reduction in business from Microsoft Corp.

On 6 March, the Indian software services company filed the petition at a Delaware district bankruptcy court against OBSA Operating Company LLC, seeking $10.65 million in damages for non-payment of dues. A day later, Sonata notified Ind...