TOKYO (Bloomberg) — Citigroup Inc., the largest US bank, moved a step closer to acquiring Japanese brokerage Nikko Cordial Corp. after Mizuho Financial Group Inc. said it plans to accept the $13.4 billion takeover offer.Mizuho, Japan's second-biggest bank, will back Citigroup's bid of 1,700 yen a share, said Masako Shiono, Mizuho's Tokyo- based spokeswoman, in a telephone interview yesterday. Mizuho's 4.8 percent stake is worth about 80 billion yen ($680 million) at the offer price.

Citigroup's earlier offer of 1,350 yen a share was opposed by Nikko's four biggest shareholders led by Chicago-based Harris Associates LP. Harris, Bermuda-based Orbis Investment Management Ltd., Southeastern Asset Management Inc. of Memphis, Tennessee, and Toronto-based Mackenzie Financial Corp., which own a combined 27 percent of Nikko, haven't publicly disclosed whether they support Citigroup's higher bid.

The offer from Citigroup probably will succeed, said Mana Nakazora, chief credit analyst at JPMorgan Securities Japan Co. in Tokyo. "Overseas funds cannot keep asking for a higher price as Citigroup will just walk away."

Money managers at Harris, Orbis and Southeastern Asset Management have said Nikko is worth at least 2,000 yen a share.

Mizuho scrapped a plan last month to acquire Nikko and instead will seek an investment banking alliance with Citigroup, two company officials said.

"Mizuho's decision will help Citigroup move a step closer to success," said Keisuke Moriyama, a Tokyo-based analyst at Nomura Holdings Inc. "It will guide other shareholders."