The Swiss National Bank, a rare central bank with listed shares, has seen a surge in interest from investors seeking alternative assets in a world of low interest rates.

Its stock has gained nearly 60 percent over the last year, but some shareholders are disgruntled with the payout that by law has been frozen at 15 francs for nearly a century.

A group of private shareholders proposed changing the bank's rules to allow a higher payment, saying the bank's foreign currency purchases had diluted the value of the Swiss franc.

"Our proposal aims to demonstrate the dilution of the purchasing power of the Swiss franc following the seven-fold increase in the SNB's balance sheet since the financial crisis," said shareholder Blaise Rossellat.

The Geneva businessman said the SNB was creating money out of thin air to buy foreign assets and not investing in Switzerland.

He said it was a perfect coincidence that SNB shares were quoted at 1,750 francs at the end of 2016, seven times more than its nominal value of 250 francs.

The SNB dividend is capped at 6 percent of its share capital of 25 million francs, allowing payment of 1.5 million francs.

For 2016 it paid 1.7 billion francs to the federal government and cantons. Remaining profit went into SNB reserves.

The rebel shareholders wanted a payout limit of 6 percent of the market value of the SNB's shares, which could have potentially increased the dividend to 105 francs.

"We are being treated as third-class shareholders," one supporter of the motion told fellow investors.

The motion was aimed not simply at a higher payout, but also to limit the central bank's foreign currency inventions and foster a debate about money creation and the effect on the Swiss economy, Rossellat said.

"The seven-fold multiplication between the historical price of SNB shares and the current market price is a symptom that something is rotten in the monetary kingdom," he said.

The SNB board opposed the motion, which was defeated with 87 percent of votes against a change. Individual shareholders' voting rights are capped at 100 votes, skewing the results. Cantons and cantonal banks control the majority.

SNB shares fell 2.8 percent to 1,845 francs by 1050 GMT.

(Reporting by John Revill, editing by David Evans)

By John Revill