United Continental Holdings is offering notified holders of the outstanding principal amount of its 4.5 per cent senior limited-subordination convertible notes due 2021, an optional redemption of all outstanding notes on February 10, 2014. On the date given, United will redeem the full outstanding principal amount of the notes at their full cash value, plus accrued and unpaid interest. The notes are convertible into shares of the company's common stock. The current conversion rate is 30.6419 shares of common stock per $1,000 principal amount of the notes, and the conversion price is $32.64. Shares in the company jumped as much as 12.6 per cent on 9 January after it announced its December revenue, which rose 12.5 per cent on a per seat mile basis.