The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.

NEW YORK (

Trefis

) -

Walgreens

(WAG)

recently announced that it was selling its prescriptions benefits management business to Catalyst Health Solutions for $525 million in cash.

We

noted recently

that

CVS Caremark

(CVS) - Get Report

is taking a different strategy and emphasizing its benefits business while Walgreens is exiting this business.

We currently value Walgreens with a $43.30 Trefis price estimate, which is slightly ahead of the current market price. Below we explore how Walgreens' divestiture will impact its business as well as look at what Walgreens' Health Initiatives will have in store for Catalyst.

Exiting the prescription benefits management (PBM) business will help Walgreens accelerate its outlined strategy of broadening its pharmacy, health and wellness services by focusing on upgrading its drugstores and further expanding its retail footprint by opening more stores and/or acquiring independent pharmacies.

While PBM has relatively lower operating expenses compared to filling prescriptions at the drugstores, the latter brings in additional sale of merchandise from each consumer visit. No wonder, Walgreens has been expanding its grocery offering and even started selling its own in-house beer to attract more foot traffic at its locations

By buying Walgreens prescription benefits management unit, Catalyst expects to increase the number of prescription benefits customers from its current 7 million to 18 million, more than doubling the number of prescriptions covered from 80 million to 165 million in the process.

Catalyst, now the fourth largest PBM with a market cap of about $2 billion, competes with the bigger players such as

Medco Health Solutions

(MHS)

,

Express Scripts

(ESRX)

and CVS Caremark, each with a market cap in excess of $20 billion. Catalyst has been trying to acquire scale with the $225 million acquisition of Independence Blue Cross's FutureScripts pharmacy benefits management business in September 2010.

We currently estimate Walgreens to make up almost 19.4% of prescriptions filled annually in the US. Sale of Walgreens' PBM business brings in close to 85 million additional prescriptions filled at Catalyst. The sale will translate into Walgreens losing its share of the prescriptions filled in the US to around 17.1% in 2011.

However, the $525 million cash raised from the sale will translate into higher growth in the number of retail stores and an increase in the revenue per square foot at existing stores from upgrades. If the revenue per square foot increases from our current estimate of $323 to over $390, this could lead to close to 10% upside to our price estimate for Walgreens' stock.Our base estimates for Walgreens project a 6.4% year-on-year growth in the number of drugstores reaching 12,600 stores at the end of our forecast period. Given the focus on expanding its retail footprint, there should be upside to this estimate.

You can modify the charts above to see how these factors impact our price estimates independently prior to the sale. See our full analysis for Walgreens

here .

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