MUMBAI: Lenders of Kingfisher Airlines Ltd have invoked pledge on 3.15 mln United Spirits Ltd shares offered as collateral by the promoters, according to a regulatory filing by United Spirits. Kingfisher Airlines and United Spirits have common promoters in Vijay Mallya and United Breweries Holdings. The invocation of the pledge suggests that the lenders might tender these shares in the ongoing open offer for United Spirits. This could not, however, be independently confirmed. Diageo Plc and associate Relay B.V. have made an open offer to acquire up to 37.78 mln United Spirits shares at 3,030 rupees per share. The open offer ends on Thursday. Shares of United Spirits ended 2% higher at Rs 2802.40 on the National Stock Exchange.