Updated from 8:13 a.m. EST

Symantec

(SYMC) - Get Report

and

Veritas Software

(VRTS) - Get Report

Thursday said they will merge in an all-stock deal.

Based on Symantec's closing stock price of $27.38 on Dec. 15, the transaction is valued at approximately $13.5 billion.

The two Silicon Valley-based software companies have been discussing a deal for more than a month.

Under the agreement announced by the two companies, Veritas stock will be converted into Symantec stock at a fixed exchange ratio of 1.1242 shares of Symantec common stock for each outstanding share of Veritas common stock. The deal price represents about a 9.5% premium for Veritas shareholders.

Veritas shares lost 17 cents, or 0.6%, to $27.94 in early Thursday trading. Symantec recently fell $2.16, or 7.9%, to $25.22.

The transaction, which is expected to close in the second quarter of 2005, will be accretive in the first combined year of operations.

On Monday,

Oracle

(ORCL) - Get Report

announced a definitive agreement to acquire

PeopleSoft

(PSFT)

for $10.3 billion, ending the software industry's most bitter takeover saga.