MUMBAI, Aug. 27 -- Shares of Hindustan Aeronautics (HAL) tanked 13% on Thursday following reports that the central government plans to divest its 15% stake in the company through a public offering of shares.

At 1240 pm, shares of HAL traded at Rs.1,023.45 apiece, down 13.1% from its previous close, while the benchmark Sensex was up 0.47% to 39258 points.

The government will sell about 10% stake, with an option to sell a further 5% in the company, according to a stock exchange filing. At a floor price of Rs.1,001 a share, the sale could fetch the Centre as much as Rs.5,020 crore.

Retail investors will get a 5% discount on the offer price. The floor price is at a nearly 15% discount to HAL's closing price of Rs.1,177.80 on Wednesday.