Bidding for the publication rights to Hillary Clinton's memoirs about her White House years is said to have reached more than $7.5m, approaching the record for a non-fiction book.

The US president, Bill Clinton, is also expected to write his memoirs, but those by first ladies tend to sell better.

"The expectation, realistic or not, is that the wives will be more candid than their husbands," said one publisher.

The Pope got $8.5m (£5.9m) six years ago for his memoirs and former president Ronald Reagan was paid more than $8m in 1989.

"Many others have imputed thoughts and feelings to me," says Mrs Clinton, who is expected to break with convention and ask for full payment in advance. "I would like to have the chance to sort my own out and to share those."

She will address the scandals of her husband's two terms, including the Monica Lewinsky affair. "That's another issue that I'd probably like to put into my own words so that people could make their own judgments," she said.