UPDATE 1-Exelon sees $65 mln charge due to healthcare reform

* To take charge in Q1

* Annual income tax expense to rise $10 mln-$15mln

April 1 (Reuters) - Exelon Corp (EXC.N), the largest operator of nuclear plants in the United States, expects a non-cash charge of about $65 million in the first quarter of 2010 due to the recently passed healthcare reform law.

The reduced income tax deductions are also estimated to increase Exelon's total annual income tax expense by about $10 million to $15 million, the company said in a filing with the U.S. Securities and Exchange Commission.

Exelon joins a growing list of big U.S. employers including AT&T Inc (T.N), Boeing Co (BA.N) and Caterpillar Inc (CAT.N) bracing for a financial pinch from the overhaul.

The reform includes a change to U.S. tax law that no longer allows companies to deduct from their taxable income a subsidy paid by the federal government to help underwrite prescription-drug coverage for retired workers.

For a factbox on other companies planning to take a charge related to healthcare reform click: [ID:nN0178243]

Shares of Exelon closed at $44.28 Thursday on the New York Stock Exchange. (Reporting by Krishna N. Das in Bangalore; Editing by Anne Pallivathuckal)