JOHANNESBURG (Bloomberg) - Aquarius Platinum Ltd., a producer of the metal in South Africa and Zimbabwe, fell the most in a month in London trading after saying it will sell shares to fund a repurchase of stock from Impala Platinum Holdings Ltd.

Aquarius slid as much as 6.7 percent, the steepest decline since March 17, after saying it would buy Impala's 8.4 percent stake for £143.8 million ($283 million) and its 20 percent holding in a South African unit for $504.9 million. Bermuda-based Aquarius will fund the purchase with reserves, debt and a $400 million sale of shares to institutional investors, it said.

Morgan Stanley is selling 23.1 million shares in Aquarius for between £7.75 and £8, according to an e-mail from Morgan Stanley sent to clients.

The shares dropped as much as 57 pence to 793.5 pence, and traded at £8 pence as of 10.43am in London, giving Aquarius a market value of £2.1 billion. Impala declined 50 cents to 333 rand in Johannesburg trading, valuing the world's second- biggest platinum producer at 210.3 billion rand ($26.3 billion).

Impala and Aquarius jointly own the Mimosa mine, east of Bulawayo, in Zimbabwe, where the government faces protests over a disputed March 29 election.