FirstGroup Plc, the operator of Greyhound buses and British trains, is attracting interest from buyout firms including CVC Capital Partners as it conducts a review of the business, people familiar with the matter said. The buyout firm has not made a formal bid and deliberations are in early stages, the people said, asking not to be identified as the details aren’t public. FirstGroup, which has a market value of 1.2 billion pounds ($1.5 billion), rejected proposals from Apollo Global Management LLC in May, saying they “fundamentally undervalued” the business.