NEW YORK (CNN/Money) - An upgrade of a tech heavyweight and another billion-dollar merger will greet investors when the U.S. markets open for trading Monday.

Investment bank J.P. Morgan upgraded the world's largest chipmaker Intel Corp. to "overweight" Monday. The firm also raised its sales and earnings-per-share estimates for the fourth quarter and the full year.

Shares of Intel (INTC: Research, Estimates) gained 30 cents to $34.17 in before-hours trading Monday.

Elsewhere, printing services firm R.R. Donnelley said Sunday it will buy Canadian commercial printer Moore Wallace for $2.8 billion plus debt, extending its range of printed products.

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The deal will enable Donnelley, a high-end publisher of catalogs, magazines and other voluminous material, to add nut-and-bolts items such as labels and bills to its repertoire. Moore Wallace shareholders will receive 0.63 share of Chicago-based R.R. Donnelley for each Moore Wallace share held.

The deal values Moore Wallace at $17.66 per share, a 16 percent premium to its $15.25 Friday closing price on the New York Stock Exchange, Donnelley said. Donnelley (DNY: Research, Estimates) shares closed at $28.03 Friday.

Warehouse club operator PriceSmart Inc. said Monday it will restate results for last year and the first nine months of 2003 after an internal probe found it had improperly inflated sales.

The company, which runs 29 warehouse clubs, mostly in Latin American countries, said some transactions had improperly been booked as sales, resulting in sales being inflated by $16.6 million in 2002 and by $12.7 million through the first nine months of 2003.

PriceSmart (PSMT: Research, Estimates) shares closed at $9.23 last week.

Quest Diagnostics Inc., a provider of medical diagnostic services, said Monday that Surya Mohapatra will succeed Kenneth Freeman as chief executive officer in 2004.

The company, based in Teterboro, New Jersey, said Freeman would remain as chairman after May 2004. Mohapatra is currently the company's president and chief operating officer.

Shares of Quest (DGX: Research, Estimates) closed at $66.35 Friday.