The S&P 500 and S&P 100 indices will undergo a makeover at the close of trading Wednesday, the last day of 2008, following the finalization of three mergers of financial companies.

Merrill Lynch

( MER) and

Wachovia

(WB) - Get Report

, acquired earlier this year by

Bank of America

(BAC) - Get Report

and

Wells Fargo

(WFC) - Get Report

, respectively, will be deleted from the S&P 500 and S&P 100 indices at the close of trading, pending final approvals.

In October, Wells Fargo said will pay $15.1 billion for Wachovia in an all-stock transaction, beating out a previous bid by

Citigroup

(C) - Get Report

that would have seen the Federal Deposit Insurance Corp. take on the majority of risk in Wachovia's loan portfolio. That followed the September acquisition of Merrill Lynch by Bank of America in a deal worth $50 billion, which came on the heels of the

Lehman Brothers

bankruptcy.

Amazon.com

(AMZN) - Get Report

will replace Merrill and

Costco Wholesale

(COST) - Get Report

will take the place of Wachovia on the S&P 100. S&P MidCap 400 constituent

SCANA Corp.

(SCG)

will replace Merrill Lynch in the S&P 500, and

Owens-Illinois

(OI) - Get Report

will replace Wachovia in the S&P 500.

Additionally, S&P MidCap 400 constituent

FLIR Systems

(FLIR) - Get Report

will replace

National City

in the S&P 500.

PNC Financial

(PNC) - Get Report

said in October it will buy National City for $5.2 billion in stock, in a deal that closed earlier this month.

As part of the deal, PNC said it had been accepted to take part in the U.S. Treasury's $250 billion capital initiative under the Troubled Asset Relief Program, or TARP, by selling $7.7 billion of preferred stock and related warrants to the government.

The S&P 500 has already deleted several financial companies over the course of 2008, many of which were casualties of the credit crisis.

Washington Mutual

, Lehman,

Freddie Mac

( FRE),

Fannie Mae

( FNM),

Countrywide

,

Ambac Financial

( ABK),

Bear Stearns

, and

Commerce Bancorp

were all replaced on the S&P 500 over the last twelve months.