LONDON (Bloomberg) — Aquarius Platinum Ltd., a producer of the metal in South Africa and Zimbabwe, rose the most in a month in London trading after Seymour Pierce Ltd. raised its rating on the stock and platinum advanced.

The shares rose 67.5 pence, or 9.4 percent, to 787 pence by close of trading in London, the biggest jump since March 26. The stock fell a combined 9.8 percent in the previous two trading sessions.

The rating on the company was raised to a "buy" from "hold" today by Seymour Pierce after Aquarius on April 24 said it expected production to be little changed this year. That's better than many other platinum producers, analysts Asa Bridle and Charles Kernot said in a report.

Power constraints in South Africa, which accounts for more than three-quarters of the world's platinum production, have helped drive up prices 29 percent this year. The metal reached a record on March 4 and rose for the first time in four days in London trading yesterday.

Aquarius has a market value of £1.98 billion ($3.9 billion).

• Yesterday Aquarius completed the buyback of stakes in the company and its Aquarius Platinum South Africa unit held by Impala Platinum Holdings Ltd.

The company paid £143.8 million ($285 million) for Impala's holdings, Aquarius said yesterday in a statement distributed by Business Wire.