Indian retailer FirstCry is set to withdraw its papers for an up to $500 million IPO as early as next week, after India's markets regulator raised questions over key metrics it disclosed to investors, said three sources with direct knowledge of the issue.

FirstCry, backed by SoftBank, TPG and India's Mahindra and Mahindra sells baby products, including clothes, diapers and toys, seeking to tap the market for new parents in the world's most populous country.

FirstCry parent BrainBees filed papers with India's Securities and Exchange Board of India last December for an IPO that would have been one of the country's biggest this year. While it filed to raise about $215 million via fresh shares, it plans to raise $300 million more via sale of existing shares, the sources said.