Quest Diagnostics Inc. (NYSE: DGX) announced an agreement to acquire smaller rival Celera Corp. (Nasdaq: CRA), a maker of diagnostic tests, for $8 per share to gain immediate access to genetic tests and pipeline of biomarkers.

The deal is valued at about $344 million, net of $327 million in acquired cash and short-term investments.

The transaction price represents a 28 percent premium to Celera's closing price of $6.27 on Thursday.

For Quest Diagnostics, this is an important transaction which will further strengthen our leadership position in molecular diagnostics discovery and development and drive sustainable revenue growth, said Surya Mohapatra, Chief Executive Officer of Quest Diagnostics.

Quest Diagnostics said it expects the deal to reduce to its GAAP earnings per share by an immaterial amount this year. The company expects Celera to add just over 1 percent to its 2011 revenue growth, assuming a close of the transaction at the end of April.

On Friday, Celera reported a net loss of $24.6 million or 30 cents a share for 2010, compared with a net loss of $25.0 million (on a restated basis) or 31 cents per share last year. Celera generated revenue of $128 million for the full year.

Alameda, California-based Celera was founded to sequence the human genome and identify links between genetic variations and disease states. Celera's current research and development pipeline is focused on cardiovascular disease and cancer and is expected to produce significant value, Quest Diagnostics said.

Celera also commercializes a wide range of molecular diagnostic products through Abbott and has licensed other relevant diagnostic technologies developed to provide personalized disease management in cancer and liver diseases.

Shares of Quest Diagnostics closed Thursday's trading at $54.20.