Kohlberg Kravis Roberts & Co., Blackstone Group and a group of takeover firms agreed to acquire TDC A/S, Denmark’s former phone monopoly, for $15.3 billion in the biggest leveraged buyout since RJR Nabisco Inc. 16 years ago.

KKR, Blackstone, Apax Partners Worldwide LLP, Permira Advisers Ltd. and Providence Equity Partners Inc. offered 382 kroner in cash for each share in Copenhagen-based TDC, Denmark’s largest phone company, they said in a statement today. The offer is 5.5% more than yesterday’s closing price and values TDC’s equity at 76 billion kroner ($12 billion).

The TDC purchase caps more than three months of talks. Private-equity firms have this year lost out to industry buyers in auctions including Italy’s Wind SpA. TDC became a more likely takeover candidate after SBC Communications Inc., the second-largest U.S. local-telephone company, sold all its shares in the Danish company last year for about half of today’s offer price.

“The price is quite high” and reflects “a high level of cash flow,” said Richard Speetjens, a fund manager at Van Lanschot Asset Management in Den Bosch, the Netherlands, which oversees about $4.4 billion. Van Lanschot sold its TDC shares “some time ago,” he said.

Including net debt, or the so-called enterprise value, the buyers said they are paying $15.3 billion for TDC, making it the largest buyout since KKR’s $31.4 billion takeover of U.S. cookies-to-cigarettes maker RJR Nabisco in 1989.

TDC shares rose 16.5 kroner, or 4.6%, to 378.5 kroner in Copenhagen, the highest level in more than four years. Before today, takeover speculation led to a 56% jump in the stock this year.