SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer
Pursuant to Rule 13a-16 or 15d-16 of the

Securities Exchange Act of 1934

For the month of December, 2010

Commission File Number 1-14668

COMPANHIA PARANAENSE DE ENERGIA

(Exact name of registrant as specified in its charter)

Energy Company of Paraná

(Translation of Registrant's name into English)

Rua Coronel Dulcídio, 800
80420-170 Curitiba, Paraná
Federative Republic of Brazil
(5541) 3222-2027

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.  Form 20-F ___X___ Form 40-F _______

 Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.  

Yes _______ No ___X____

COMPANHIA PARANAENSE DE ENERGIA - COPEL Corporate Taxpayer’s ID (CNPJ/MF) 76.483.817/0001-20 Publicly-Held Company CVM Register No. 1431-1 SEC (CUSIP) Register 20441B407 – Preferred “B” SEC (CUSIP) Register 20441B308 – Common LATIBEX Register 29922 – Preferred “B”

NOTICE TO THE MARKET

Companhia Paranaense de Energia – COPEL, a company that generates, transmits and distributes power to the State of Paraná, with shares listed on the BM&FBOVESPA (CPLE3, CPLE5, CPLE6), NYSE (ELP) and LATIBEX (XCOP), hereby informs its shareholders and the market in general that it received the following information from BlackRock, Inc. in compliance with Article 12 of CVM Instruction 358/02:

CIA PARANAENSE DE ENERGIA – COPEL

Rua Coronel Dulcídio, 800 – 3º andar

CEP: 80420-170 – Curitiba – PR - Brasil

Attn: Mr. Rafael Iatauro

Investor Relations Officer

Phone: 55 41 3222-2027

Fax: +55 (41) 3331-3136

E-mail: rafael.iatauro@copel.com

December 1^st, 2010

Companhia Paranaense de Energia – Announcement of Sale of Relevant Interest

Dear Sirs,

1The undersigned BlackRock, Inc. (“BlackRock”), hereby informs, on behalf of some of its clients and in its capacity as an investment manager, that it sold class B preferred shares issued by Companhia Paranaense de Energia (“COPEL”), as a result of which its combined interest on November 30, 2010 totaled 3,926,563 class B preferred shares and 2,234,971 American Depositary Receipts representatives of class B preferred shares (“ADRs”), equivalent to approximately 4.79% of the class B preferred shares issued by COPEL.

2In compliance with Article 12 of Instruction 358 issued by the Securities and Exchange Commission of Brazil (“CVM”), issued on January 3^rd 2002, BlackRock hereby requests COPEL’s Investor Relations Officer to disclose the following information to the CVM and other competent bodies:

(i)BlackRock is headquartered at 40 East 52^nd Street, New York, New York 10022-5911, United States of America;

(ii)The combined interest held by BlackRock totaled 3.926.563 class B preferred shares and 2.234.971 ADRs issued by COPEL, as detailed in item 1 above;

COMPANHIA PARANAENSE DE ENERGIA - COPEL Corporate Taxpayer’s ID (CNPJ/MF) 76.483.817/0001-20 Publicly-Held Company CVM Register No. 1431-1 SEC (CUSIP) Register 20441B407 – Preferred “B” SEC (CUSIP) Register 20441B308 – Common LATIBEX Register 29922 – Preferred “B”

(iii)the above-mentioned shareholding interest is strictly for investment purposes and there is no intention of altering COPEL’s shareholding control or management structure;

(iv)BlackRock does not hold convertible debentures issued by COPEL; and

(v)BlackRock has not entered into any contracts or agreements regulating the exercise of voting rights or the purchase and sale of securities issued by COPEL.

3We are available for further information or clarification in this regard.

Sincerely,

BlackRock, Inc.

By proxy Christian Roschmann

Curitiba, December 2, 2010

Rafael Iatauro

Chief Financial and Investor Relations Officer

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: December 3, 2010

COMPANHIA PARANAENSE DE ENERGIA – COPEL
By:	/S/  Raul Munhoz Neto
	Raul Munhoz Neto  CEO

FORWARD-LOOKING STATEMENTS

This press release may contain forward-looking statements. These statements are statements that are not historical facts, and are based on management's current view and estimates of future economic circumstances, industry conditions, company performance and financial results. The words "anticipates", "believes", "estimates", "expects", "plans" and similar expressions, as they relate to the company, are intended to identify forward-looking statements. Statements regarding the declaration or payment of dividends, the implementation of principal operating and financing strategies and capital expenditure plans, the direction of future operations and the factors or trends affecting financial condition, liquidity or results of operations are examples of forward-looking statements. Such statements reflect the current views of management and are subject to a number of risks and uncertainties. There is no guarantee that the expected events, trends or results will actually occur. The statements are based on many assumptions and factors, including general economic and market conditions, industry conditions, and operating factors. Any changes in such assumptions or factors could cause actual results to differ materially from current expectations.