Nara Bancorp Inc. and Center Financial Corp. said that shareholders of each bank on Thursday approved their planned $286 million merger that will create the nation’s largest Korean-American bank.

The Koreatown bank holding companies said that about 99 percent of the shares voted by each group of shareholders were in favor of the deal. About 74 percent of Nara’s outstanding stock and 77 percent of Center Financial’s stock were voted. In the deal, Center stockholders will receive 0.78 of a share of Nara stock for each of their Center shares, with Nara shareholders owning about 55 percent of the new company.

In addition to approving the merger, Nara shareholders also approved increasing the authorized number of common shares to 150 million shares to facilitate the transaction.

The combined institution is expected to have assets of $5.3 billion and deposits of $4 billion. There will be 45 branches, located primarily in California. The banks, which have not announced what the combined bank will be called, said they expect to complete the merger during the fourth quarter.

In Thursday midday trading on the Nasdaq, Nara shares were unchanged at $5.99 and Center Financial shares were up less than 1 percent to $4.61.