Willis Group, the world's third-largest insurance broker, is planning to pay back some of its $935m (£682m) of long-term debt by placing 20 million shares on the New York Stock Exchange.

The company is expecting to raise up to $270m (£197m) when trading in the shares begins on Tuesday.

The shares are likely to be priced at $13.50 (£9.85) each, which is considerably higher than the indicative pricing of between $10 (£7.20) and $12 (£8.75) when Willis announced the placing in April.

Willis has given the stockbrokers underwriting the offering permission to introduce a further block of three million shares on to the market if the first placing is oversubscribed.

Chairman and chief executive Joseph Plumeri said the proceeds from the sale would be used to pay off the company's long-term debt. He said in a statement: “We intend to either redeem some of the preference shares in TAII, a Willis group subsidiary, or to repay debt from Willis North America, or a combination of both.”

Company rec-ords revealed that Willis had £682m ($935m) long-term debt of as of March 31, 2001.