NEW YORK (Bloomberg) — Citigroup Inc. said yesterday it won't raise its $13.4 billion takeover bid for Japan's Nikko Cordial Corp. further and expressed confidence the offer will succeed.The cash offer of 1,700 yen per share expires April 26, Citigroup said at a press briefing in Tokyo yesterday. Citigroup also announced that Nikko would have to pay a 5 billion-yen ($43 million) fee should it break up the purchase. Citigroup on March 6 offered 1,350 yen per share.

Bermuda-based Orbis Investment Management Ltd., Harris Associates LP of Chicago and Southeastern Asset Management Inc. of Memphis, Tennessee, rejected Citigroup's initial offer, saying the company is worth at least 2,000 yen share.

"We won't be increasing the price," Douglas Peterson, Citigroup's Japan head, said at the briefing. "We are very confident with this tender offer and we'll successfully complete this acquisition."

Citigroup yesterday boosted its offer by 26 percent after the Tokyo Stock Exchange declined to delist Nikko, putting shareholders who rejected the earlier bid in a better bargaining position. Nikko shares surged 13 percent to a ten-month high of 1,690 yen today.

"The increase shows Citigroup is serious about buying Nikko," said Hiroyuki Maekawa, an analyst at Deutsche Securities Inc. in Tokyo.

Four investors controlling more than a quarter of the stock turned down the earlier offer as too low. Nikko would give New York-based Citigroup more than 100 branches in Japan and an additional 30 trillion yen ($257 billion) of clients' assets in Asia's biggest economy.

Toronto-based Mackenzie Financial Corp. also turned down the bid, people familiar with the matter said this week. Together, the four control about 27 percent of Nikko.

The revised offer values Nikko at 2.04 times book value, from 1.62 times for the first bid. Nomura Holdings Inc., Japan biggest brokerage, has a price-to-book ratio of 2.26 and Citigroup trades at 2.08 times book value.

Nikko yesterday said it supports the new bid, and repeated that it plans to list its asset management division. After the takeover, Citigroup will have the right to propose two to four members for Nikko's board, the company said in a release handed out at the Tokyo press conference.