Richard Kinder, CEO of oil and gas pipeline operator Kinder Morgan, has launched a management buyout bid for the company. But rating agency Standard & Poor's has warned that it may cut Kinder Morgan's ratings to 'junk' status, as it expects the bid to be highly leveraged. Firms with junk credit ratings face higher borrowing costs and are less attractive credit counterparties.

"The sharp increase in debt contemplated in the buyout offer would likely lead to a ratings downgrade well into the 'BB'