Oracle's ( ORCL - Get Report) ultimately successful move to gobble up rival PeopleSoft ( PSFT drew rounds of praise Tuesday from Wall Street, including three upgrades. But one analyst took a more critical view of the blockbuster deal and downgraded Oracle's stock.

Oracle enjoyed upgrades to the equivalent of buy ratings from analysts at Piper Jaffray, Prudential, and Friedman Billings Ramsey, who raised their price targets to $17, $18 and $17, respectively. (Piper has received pay for noninvestment banking services from Oracle and PeopleSoft; Prudential doesn't have an investment banking arm; and FBR hasn't done banking with Oracle.)

The reasons cited by the analysts for their upgrades included solid second-quarter results, also released Monday, and accretion potential from the PeopleSoft acquisition, which the company said would add at least 8 cents a share to fiscal 2006 earnings.

However, Sanford C. Bernstein analyst Charlie Di Bona took the contrarian view, downgrading his rating on Oracle to market perform from outperform. He suggested the recent rally in Oracle shares already appears to reflect much of the potential accretion from the PeopleSoft deal, while not necessarily accounting for the potential operational risks of integrating the two companies.

Oracle's estimate on PeopleSoft's accretion potential fell significantly short of Di Bona's estimate of 13 cents a share in fiscal 2006. While most analysts focused on Oracle's unexpectedly strong second-quarter application sales, Di Bona highlighted the "meager growth" of Oracle's database business, at only 5% in the second quarter and an even smaller 1% in constant currency. (Di Bona's firm doesn't do investment banking but holds shares of PeopleSoft.)

After jumping 10% Monday, Oracle's stock was recently down a modest 25 cents, or 1.7%, to $14.38. Shares of PeopleSoft were flat at $26.42 after gaining 10.3% Monday.