(Commission File No. 1-14862 )

EXHIBIT 20

(CVM Ruling No. 481/09)

RIGHT TO WITHDRAW

1.         Describe the event that entailed or will entail the withdrawal and its legal grounds

Answer: The merger by Braskem S.A. (“Braskem”) of shares of its controlled company Quattor Participações S.A. (“Quattor”) (“Merger of Shares”) shall give Braskem’s shareholders the right to withdraw, under article 252 of Law No. 6,404/76 (“Corporation Law”).

2.         Inform the shares and classes to which the withdrawal applies

Answer: Only common shares and class “B” preferred shares of Braskem shall grant its holders the right to withdraw. Class “A” preferred shares of Braskem shall not grant its holders the right to withdraw, since such shares have liquidity and dilution, pursuant to article 137, II of the Corporation Law.

3.         Inform the date of the first publication of the call notice of the meeting, as well as the date of the communication of the material fact pertaining to the resolution that entailed or will entail the withdrawal

Answer: The Material Fact that disclosed the Merger of Shares, transaction which will entail the right to withdraw, was disclosed on January 22, 2010. The call notice of the meeting that will resolve the Merger of Shares shall be published for the first time on June 02, 2010.

4.         Inform the term to exercise the right to withdraw and the date that will be considered for purposes of establishing the holders of the shares that will be entitled to exercise the right to withdraw

Answer: The right to withdraw shall only be ensured as regards the shares that the shareholders that hold common shares and class “B” preferred shares of Braskem provenly held on January 22, 2010, prior to the market opening, publication date of the Material Fact that informed the market of the Merger of Shares. The term to exercise the right to withdraw is of 30 days as from the date in which the minutes of Braskem’s meeting that approves the Merger of Shares are published.

Other information about the exercise of the right to withdraw by Braskem’s shareholders will be disclosed in a Notice to the Shareholders to be disclosed on a date after the approval of the Merger of Shares by Braskem’s general meeting.

5.         Inform the amount of the reimbursement per share or, if it is not possible to determine it previously, the administration’s estimate about such amount

Answer: The amount of the reimbursement of the shares subject to the exercise of the right to withdraw shall be R$ 9.15237722 (nine reais, fifteen centavos and fraction) per share.

6.         Inform the calculation form of the amount of the reimbursement

Answer: The amount of the reimbursement corresponds to the ratio of the division of Braskem’s net equity amount, except for the treasury shares, by the amount of shares issued by the Company, pursuant to the last approved balance sheet of Braskem of December 31, 2009.

7.         Inform if the shareholders will be entitled to request a special balance sheet

Answer: The shareholders shall have the right to request a special balance sheet, pursuant to article 45, paragraph 2, of the Corporation Law.

8.         If the amount of the reimbursement is determined by an appraisal, list the experts or specialized companies recommended by the administration

Answer: Not applicable.

9.         In the event of merger, merger of shares or consolidation involving controlling and controlled companies or companies under common control

a.         Calculate the replacement ratios of the shares based on the amount of the net equity at market prices or other criteria accepted by the CVM

Answer: As set forth in article 264 of the Corporation Law, Braskem and Quattor requested from CVM, on May 06, 2010, that the economic and financial appraisal report of Braskem and Quattor that served as basis to determine the replacement ratio applicable to the Merger of Shares be used to comply with the provisions in the main section of article 264 of the Corporation Law. Such report indicates a replacement ratio of 0.188558631820 common share issued by Braskem for each common share issued by Quattor.

b.         Inform if the replacement ratios of the shares set forth in the transaction protocol are less advantageous than the ones calculated pursuant to item 9(a) above

Answer: The replacement ratio set forth in the protocol of the Merger of Shares is equal to the one ascertained in the report that will be used to comply with article 264 of the Corporation Law, which shall be subject to CVM’s authorization, as mentioned in item “a” above.

c.         Inform the amount of the reimbursement calculated based on the amount of the net equity at market prices or other criteria accepted by CVM

Answer: The right to withdraw set forth in article 264, paragraph 3 of the Corporation Law does not apply to Braskem’s shareholders, since such provision gives the option of exercising the right to withdraw by the price per share calculated pursuant to article 264, if the replacement ratio calculated under the terms set forth therein is more advantageous than the ratio proposed by the companies’ administrations only to the shareholders of the controlled company (Quattor).

10.       Inform the equity value of each share, ascertained pursuant to the last approved balance sheet

Answer: The equity value per share of Braskem ascertained pursuant to the balance sheet of December 31, 2009 is R$ 9.15237722 (nine reais, fifteen centavos and fraction).

11.       Inform the quotation of each class or kind of shares to which the withdrawal applies in the markets in which they are traded, identifying:

i.          Minimum, average and maximum quotation for each year, for the last three (03) years

ii.         Minimum, average and maximum quotation for each quarter, for the last two (2) years

iii.        Minimum, average and maximum quotation for each month, for the last six (6) months

iv.        Average quotation for the last ninety (90) days

Note: BAK (US$/share), XBRK (€/share), BRKM (R$/share)

SIGNATURES

        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.