Agarwal has acquired about 10.77 million shares of the company or 3.94 per cent stake between December 13, 2013 and March 21, 2014 in as many as 28 transactions, Vedanta's filings to the London Stock Exchange (LSE) showed. The value of share purchases are estimated at over 104 million pounds.
In past one year (since March 31, 2013), stake of Vedanta chairman in the company has risen by 4.53 per cent.
The gradual build up of Agarwal's stake in the mining giant has led to delisting buzz, industry insiders say. However, no official word was available on this as a company spokesperson did not respond to calls seeking comment.
Terming it an "unusual" move, an analyst who closely tracks Vedanta, said that the rise of nearly 4 per cent in 4 months in promoter's stake has not been witnessed since its listing on the LSE on December 10, 2003.
Moreover, Agarwal's stake in Vedanta has risen by over 15 per cent since its listing and he has been increasing his stake in the company every year, the analyst said.
Vedanta CEO M S Mehta had said on January 31 in an analyst call that "so far there is no indication of what number we can go up to." He was replying to a question on whether there is any indication from the promoters on the level at which promoters would cap purchases.
As per the filings, Agarwal had made his last two purchases on March 19 and 20, when he acquired 9,08,746 company shares, amounting to 0.34 per cent stake, for 7.44 million pounds.
He controls Vedanta through 100 per cent owned Volcan Investments Ltd, which has been incorporated in the Bahamas.
In recent times, the metals and mining conglomerate has been struggling with fall in revenue due to lower commodity prices and regulatory issues.
Yesterday, Indian Income Tax authorities had surveyed offices of its main operating firm Sesa Sterlite Ltd in connection with its creation, which took place last year after merger of Sterlite Industries and other Vedanta entities into Sesa Goa.
During April to December, 2013, Vedanta had reported 9 per cent decline in its EBITDA (earnings before interest, taxes, depreciation, and amortisation), or core profits, at USD 3.348 billion.
Vedanta Resources plc shares have lost about one third of its value in a year. The scrip removed from the FTSE-100 index last year. On Friday, the company's shares closed at about 848 pence on the LSE, up around 2 per cent.