Quest Diagnostics Incorporated , the nation's leading provider of diagnostic testing, information and services, announced today the preliminary calculations regarding the consideration to be paid to Unilab shareholders who had elected cash in the previously announced exchange offer. The deadline for delivering Unilab shares tendered pursuant to notices of guaranteed delivery expired at 5:00 p.m. on Friday, February 28, 2003.

In the exchange offer, approximately 34.7 million shares were tendered for cash. Because the cash election feature of the exchange offer was over-subscribed, Quest Diagnostics estimates that Unilab shareholders who elected to receive cash in the exchange offer will receive $19.10 per share for approximately 45% of their Unilab shares and will receive 0.3424 of a share of Quest Diagnostics common stock for approximately 55% of their Unilab shares. The final proration is being calculated by the Exchange Agent, Computershare Trust Company of New York, and is expected to be completed by the close of business on Monday, March 3, 2003.

Approximately 1.2 million shares were tendered for stock. Unilab shareholders who elected to receive Quest Diagnostics common stock will receive 0.3424 of a share of Quest Diagnostics common stock for each of their Unilab shares.

On Friday, February 28, 2003, Unilab became a wholly owned subsidiary of Quest Diagnostics through a merger with another subsidiary of Quest Diagnostics. In the merger, each Unilab share that was not tendered into the exchange offer was converted into 0.3424 of a share of Quest Diagnostics common stock.

As previously announced, Quest Diagnostics is issuing approximately 7.4 million shares of its common stock (including approximately 300,000 shares reserved for the exercise of outstanding Unilab options) and paying approximately $297 million in cash for Unilab shares in connection with the exchange offer and the merger.

For additional information on the cash election exchange offer, Unilab shareholders may contact Georgeson Shareholder Communications at 212-440-9800. In addition, Merrill Lynch is the Dealer Manager for the exchange offer and may be contacted toll free at 866-276-1462.

About Quest Diagnostics

Quest Diagnostics Incorporated is the nation's leading provider of diagnostic testing, information and services, providing insights that enable physicians, hospitals, managed care organizations and other healthcare professionals to make decisions to improve health. The company offers the broadest access to diagnostic laboratory services through its national network of laboratories and patient service centers. Quest Diagnostics is the leading provider of esoteric testing, including gene-based medical testing, and empowers healthcare organizations and clinicians with state-of-the-art connectivity solutions that improve practice management. Additional company information can be found on the Internet at: http://www.questdiagnostics.com/ .

SOURCE: Quest Diagnostics Incorporated

CONTACT: Laure Park, Investors, +1-201-393-5030, or Gary Samuels, Media,
+1-201-393-5700, both of Quest Diagnostics Incorporated

Web site: http://www.questdiagnostics.com/