Walgreen to keep U.S. tax domicile after buying Alliance Boots

* Walgreen to buy remaining 55 pct of Alliance Boots

* Combined firm has more than 11,000 stores in 10 countries

* Tax "inversion" deals under pressure; Obama seeks action

* Walgreen says inversion deal not in interests of investors

* Plans $1 bln savings by fiscal 2017, share buyback (Adds comments from Obama)

By Emma Thomasson and Sruthi Ramakrishnan

Aug 6 (Reuters) - U.S. retailer Walgreen Co said it would not use a full takeover of Europe's biggest pharmacy chain, Alliance Boots, to move its domicile overseas, following fierce criticism of such tax-cutting deals at home.

Walgreen will buy the 55 percent it does not already own of Alliance Boots for 3.13 billion pounds ($5.3 billion) in cash and 144.3 million shares, giving a total deal of about $15 billion.

Walgreen shares fell as much as 16 percent to $58.30 on Wednesday.

The U.S. group said the combined company, with more than 11,000 stores in 10 countries, would keep its tax domicile in the United States, with headquarters in the Chicago area. It is targeting combined revenue for 2016 of $126-130 billion.

Walgreen's retreat is the third major possible tax "inversion" deal to collapse in recent months amid heightened political sensitivity in the United States to such transactions.

President Barack Obama told reporters on Wednesday that his administration plans to move quickly on measures to discourage the use of inversions.

"We don't want to see this trend grow," Obama said at a news conference, not specifically mentioning Walgreen, which is based in his home state of Illinois.

"That kind of herd mentality is something we want to avoid, so we want to move quickly, as quickly as possible," Obama said.

Walgreen had been under pressure from investors to shift its tax domicile to Switzerland or Britain as part of the buyout.

The pharmacy chain said it was mindful of the public reaction to a potential inversion deal and its role as an "iconic American consumer retail company with a major portion of its revenues derived from government-funded reimbursement programs".

"The company concluded it was not in the best long-term interest of our shareholders to attempt to re-domicile outside the U.S.," CEO Greg Wasson said in a statement.

He said the company could not find a structure it was sure could withstand extensive scrutiny from U.S. tax authorities.

Wasson will be chief executive of the combined company, to be named Walgreens Boots Alliance Inc. Alliance Boots Executive Chairman Stefano Pessina will be its executive vice-chairman, responsible for strategy and M&A for the combined company.