The merger closed on Wednesday and more than doubles the size of Wells Fargo, creating the fourth-largest U.S. bank by assets. Wells Fargo also has the nation's largest branch network, with more than 6,600 offices in 39 states and Washington, D.C., and one of its largest retail brokerages.

San Francisco-based Wells Fargo agreed on October 3 to buy Wachovia, beating out a smaller bid by Citigroup Inc for part of Wachovia. Citigroup's bid included government backing, while Wells Fargo's did not. Wells Fargo said Wachovia branches will keep their brand name at least for the "near future."

Regulators pushed Wachovia to find a buyer after the Charlotte, North Carolina, bank was throttled by soaring losses on "option" adjustable-rate mortgages it took on when it bought California lender Golden West Financial Corp in 2006.

Last month, Wells Fargo said it expects to write down $71.4 billion of Wachovia's $482.4 billion loan portfolio, including $36 billion of option ARMs and $9.6 billion of commercial real estate.

Analysts have said Wells Fargo appeared cautious in assessing risks in Wachovia's mortgage portfolio, but the U.S. economy and housing market have continued to deteriorate.

"We're not at the end" of the housing slump, Wells Fargo Chief Executive John Stumpf said on December 10 at a conference. "But we're starting to see some early signs that maybe we've reached the bottom in housing or close to it."

Wells Fargo is the nation's second-largest mortgage lender. It remained profitable by avoiding many of the risky loans that plagued Wachovia, caused Washington Mutual Inc's and IndyMac Bancorp Inc's failures and drove Countrywide Financial Corp into the arms of Bank of America Corp .

Wachovia shareholders received 0.1991 of a Wells Fargo share for each of their shares, valuing the bank at $5.87 per share. That's down from $59.39 when the Golden West merger was announced in May 2006, a level never again reached. Wachovia shares closed Wednesday at $5.54, down 85.4 percent in 2008.

Shares of Wells Fargo closed Wednesday at $29.48, down just 2.4 percent for the year. The KBW Bank Index <.BKX>, which includes Wells Fargo, fell 50 percent in 2008.

Wells Fargo expects the merger to result in at least $5 billion of annual cost savings, and to boost earnings per share by 20 percent or more in 2011 and higher amounts thereafter.

Including Wachovia, Wells Fargo has about $1.4 trillion of assets. Bank of America is expected Thursday to complete its purchase of Merrill Lynch & Co, creating the nation's largest bank by assets. JPMorgan Chase & Co and Citigroup also have more assets than Wells Fargo.

(Reporting by Jonathan Stempel; Editing by Eric Beech)