April 24 (Bloomberg) -- Marks & Spencer Group Plc Chief Executive Officer Stuart Rose's investment in an independent director's karaoke bars constitutes improper corporate governance, the Association of British Insurers said.

The association is asking Marks & Spencer, the U.K's largest clothing retailer, to explain how non-executive director Martha Lane Fox can be considered independent after Rose invested in her Lucky Voice company, association spokesman Erfan Hussain said today by telephone, confirming a report in the Financial Times.

The investment was not material and won't compromise Lane Fox's independence, the FT reported, citing a person close to the London-based retailer that it didn't identify.

``It's a private matter between M&S and the ABI,'' company spokeswoman Clare Wilkes said by phone.

The association has objected this month to Marks & Spencer's decision to appoint Rose as executive chairman, saying it went against corporate-governance guidelines. Association members control 15 percent of investment in the London stock market, according to a fact sheet on the group's Web site.

To contact the reporter on this story: Louisa Nesbitt in Dublin at lnesbitt@bloomberg.net

Last Updated: April 24, 2008 09:53 EDT