UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

[Rule 13d-101]

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13D-1(A) AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13D-2(A)

APAC Customer Services, Inc.

(Name of Issuer)

Common Shares, par value $0.01 per share

(Title of Class of Securities)

00185E106

(CUSIP Number)

OEP Parent LLC

OEP General Partner IV, L.P.

One Equity Partners IV, L.P.

Blackhawk Acquisition Parent, LLC

c/o One Equity Partners IV, L.P.

320 Park Avenue

New York, New York 10022

(212) 277-7689

Copy to:

Derek M. Winokur, Esq.

Dechert LLP

1095 Avenue of the Americas

New York, New York 10036

212-698-3500

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

July 6, 2011

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.   ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Section 240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Item 1. Security and Issuer

This statement on Schedule 13D (“Schedule 13D”) relates to the common shares, par value $0.01 per share (the “Issuer Common Shares”), of APAC Customer Services, Inc., an Illinois corporation (the “Issuer”). The address of the principal executive office of the Issuer is 2201 Waukegan Road, Suite 300, Bannockburn, IL 60015.

Item 2. Identity and Background

This Schedule 13D is being filed jointly by the following persons (collectively, the “Reporting Persons”):

Blackhawk Acquisition Parent, LLC is a Delaware limited liability company (“Parent”). The sole member of Parent is One Equity Partners IV, L.P., a Cayman Islands limited partnership (“OEP IV”); the sole general partner of OEP IV is OEP General Partner IV, L.P., a Cayman Islands limited partnership (“OEP GP IV”); the sole general partner of OEP GP IV is OEP Parent LLC, a Delaware limited liability company (“OEP Parent”); the sole member of OEP Parent is OEP Holding Corporation, a Delaware corporation (“OEP Holding”); JPMorgan Capital Corporation, a Delaware corporation (“JPM CC”), owns all of the outstanding capital stock of OEP Holding; Banc One Financial LLC, a Delaware limited liability company (“BOF LLC”), owns all of the outstanding capital stock of JPM CC; and JPMorgan Chase & Co., a Delaware corporation (“JPMC”), owns all of the outstanding equity interests of BOF LLC. Due to their relationship to Parent, each of OEP IV, OEP GP IV and OEP Parent may be deemed to have shared voting and investment power with respect to the Issuer Common Shares that Parent may be deemed to have beneficial ownership over as a result of the voting agreement described in Item 4 hereof. As such, OEP IV, OEP GP IV and OEP Parent may be deemed to have shared beneficial ownership over such Issuer Common Shares. Each of OEP IV, OEP GP IV and OEP Parent, however, disclaims beneficial ownership of such Issuer Common Shares.

The name, residence or business address, and present principal occupation or employment of each director, executive officer and controlling person of JPMC, BOF LLC, JPM CC, OEP Holding, OEP Parent and Parent are listed on Schedule I to this Schedule 13D. OEP GP IV and OEP IV do not have any directors or officers.

Information in this Schedule 13D with respect to the Reporting Persons is given solely by such Reporting Person, and no Reporting Person assumes responsibility for the accuracy or completeness of information provided by another Reporting Person.

During the past five years, none of the Reporting Persons (or, to the knowledge of the Reporting Persons, any of the persons listed on Schedule I hereto) (i) has been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors) or (ii) was a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

Item 3. Source and Amount of Funds or Other Consideration

As more fully described in Item 4 hereof, Theodore G. Schwartz, LTHS Revocable Trust dated April 4, 1986, CAPA Partners, L.P., Trust Four Hundred Thirty, Trust Seven Hundred Thirty, Trust 3080 and Trust 3081 (each, a “Shareholder”, and collectively, the “Shareholders”), who are the beneficial owners of an

aggregate of 19,993,429 Issuer Common Shares (the “Subject Shares”), have entered into the Voting Agreement (as defined in Item 4) with Parent. Any beneficial ownership of the Reporting Persons in the Subject Shares that may be deemed to arise from the Voting Agreement is not expected to require the expenditure of any funds. The Shareholders entered into the Voting Agreement to induce Parent to enter into the Merger Agreement described in Item 4.

Item 4. Purpose of Transaction

Merger Agreement

On July 6, 2011, the Issuer, Parent and Blackhawk Merger Sub, Inc., a wholly owned subsidiary of Parent (“Merger Sub”), entered into an Agreement and Plan of Merger (the “Merger Agreement”). Subject to the terms and conditions of the Merger Agreement, which has been approved by the boards of directors of all parties, Merger Sub will be merged with and into the Issuer (the “Merger”). Upon effectiveness of the Merger, each outstanding Issuer Common Share, other than shares owned by Parent, Merger Sub or the Issuer, any of their wholly owned subsidiaries or by any shareholders who are entitled to and properly exercise appraisal rights, will be converted into the right to receive $8.55 in cash. Consummation of the Merger is subject to certain conditions, including, among others, the approval of the Merger Agreement by the Issuer’s shareholders and the receipt of required regulatory and antitrust approvals.

Voting Agreement

As a condition and inducement to Parent entering into the Merger Agreement, the Shareholders entered into a Voting Agreement, dated as of July 6, 2011, with Parent (the “Voting Agreement”) with respect to (i) the Subject Shares and (ii) any Issuer Common Shares that a Shareholder acquires direct or indirect voting power over (including by way of share dividend, share distribution, split-up, recapitalization, combination, exchange or the like) after the date of the Voting Agreement until its termination in accordance with its terms (collectively, the “Covered Shares”).

Subject to the terms and conditions of the Voting Agreement, each Shareholder has agreed that, prior to the termination of the Voting Agreement, it shall at any meeting of the shareholders of the Issuer (or any adjournment or postponement thereof), however called, vote, or cause to be voted at such meeting, all of such Shareholder’s Covered Shares (i) in favor of the adoption and approval of the Merger Agreement and all of the transactions contemplated by the Merger Agreement (and in favor of any actions and proposals required, or submitted for approval at any meeting of the shareholders of the Issuer, in furtherance thereof), (ii) against any proposal presented to the shareholders of the Issuer for approval, if the action, transaction or agreement that is the subject of such proposal, following the approval by the Issuer’s shareholders, would reasonably be expected, directly or indirectly, to result in a breach by the Issuer of any covenant, representation, warranty or other obligation of the Issuer set forth in the Merger Agreement, (iii) against (unless contemplated by the Merger Agreement) (A) any Competing Proposal (as defined below), (B) any nominee for election to the Issuer’s board of directors other than (x) a person nominated by the Issuer’s board of directors or any committee thereof and/or (y) Theodore G. Schwartz, or (C) any other action or proposal to be voted upon by the shareholders of the Issuer if such action or proposal would reasonably be expected to prevent, impede, interfere with, delay, postpone or adversely affect the transactions contemplated by the Merger Agreement. Each Shareholder also agreed not to enter into any agreement or commitment with any person, the effect of which would violate or be inconsistent with the foregoing agreements.

In addition, each Shareholder irrevocably granted Parent and Parent’s designees its irrevocable proxy to vote such Shareholder’s Covered Shares as indicated above and agreed to waive and not exercise any rights of appraisal or rights to dissent from the Merger that he, she or it may have under applicable law.

Each Shareholder also agreed during the term of the Voting Agreement not to: (i) sell, transfer, pledge, encumber, assign or otherwise dispose of, or enter into any contract, option or other agreement with respect to, any of such Shareholder’s Covered Shares (except for transfers for estate planning or charitable purposes to certain affiliates of such Shareholder that agree to be bound by the Voting Agreement); (ii) acquire, offer to acquire, or agree to acquire, directly or indirectly, by purchase or otherwise, any material assets of the Issuer or any subsidiary or division thereof; (iii) make, or in any way participate in, directly or indirectly, any “solicitation” of “proxies” (as such terms are used in the rules of the Securities and Exchange Commission) to vote, or otherwise take any action intended to advise or influence any person with respect to the voting of, any voting securities of the Issuer, other than in support of the Merger and the Merger Agreement; (iv) make any public announcement with respect to, or submit a proposal for, or offer for (with or without conditions) any extraordinary transaction involving the Issuer or its securities or material assets; (v) form, join or in any way participate in a “group” (as defined in Section 13(d)(3) under the Exchange Act) in connection with any of the foregoing; (vi) seek in any way which may be reasonably likely to require, involve or trigger public disclosure of such request pursuant to applicable law to have any

of the foregoing amended, modified or waived or (vii) otherwise take, directly or indirectly, any actions with the purpose of avoiding or circumventing any of the foregoing or which would reasonably be expected to have the effect of preventing, impeding, interfering with or adversely affecting the consummation of the transactions contemplated by the Merger Agreement or its ability to perform the Shareholder’s obligations under the Voting Agreement.

Each Shareholder also agreed not to, and to use his, her or its reasonable best efforts to ensure that each of his, her or its representatives and affiliates do not, directly or indirectly (i) solicit or initiate, or knowingly facilitate or encourage (including by way of providing information) any inquiries, proposals or offers that constitute, or that would reasonably be expected to lead to, any Competing Proposal, (ii) participate in any negotiations regarding, or furnish to any person (other than the Issuer, any other Shareholder or any representative of such Shareholder, the Issuer or any other Shareholder) any nonpublic information with respect to, any Competing Proposal or (iii) engage in discussions with any person (other than the Issuer, any other Shareholder or any representative of such Shareholder, the Issuer or any other Shareholder) with respect to any Competing Proposal. Each Shareholder agreed that if he, she or it, or any of his, her of its representatives, at any time during the pre-closing period, received any inquiry regarding a Competing Proposal from a potential bidder or its representatives, or if any potential bidder or its representatives sought to initiate negotiations or discussions with the Shareholder related to a Competing Proposal, such Shareholder would promptly (i) advise the Issuer in writing of such Competing Proposal, inquiry or request (including the identity of the person making or submitting such Competing Proposal, inquiry or request and the material terms and conditions thereof) and (ii) provide the Issuer with copies of all documents and other written communications received by such Shareholder setting forth the terms and conditions of such Competing Proposal, inquiry or request. In addition, each Shareholder agreed to promptly inform each of his, her or its representatives and affiliates and the representatives of his, her or its affiliates of the obligations contained in the Voting Agreement and further agreed to, and agreed to ensure that his, her or its representatives and affiliates will, immediately cease and caused to be terminated any existing solicitations by such Shareholder, his, her or its representatives or affiliates, or discussions or negotiations between such Shareholder, his, her or its representatives or affiliates and any person relating to any Competing Proposal.

Each Shareholder is a party to the Voting Agreement solely in his, her or its capacity as the beneficial owner of the Subject Shares (and not in capacity as an officer or director of the Issuer or any of its subsidiaries) and nothing in the Voting Agreement shall limit or affect any Shareholder who serves as a director or officer of the Issuer or any of its subsidiaries in acting in his or her capacity as a director or officer of the Issuer or any of its subsidiaries.

“Competing Proposal” means any bona fide proposal (other than a proposal or offer by Parent or any of its subsidiaries) relating to any direct or indirect (i) merger, reorganization, share exchange, consolidation, business combination, recapitalization, dissolution, liquidation or similar transaction involving the Issuer or any of its subsidiaries, whose assets individually or in the aggregate, constitute fifteen percent (15%) or more of the consolidated assets of the Issuer as determined on a book-value basis; (ii) the acquisition by any person of 15% or more of the assets of the Issuer and its subsidiaries, taken as a whole as determined on a book-value basis; (iii) the acquisition by any person of 15% or more of the issued and outstanding Issuer Common Shares or (iv) any purchase, acquisition, tender offer or exchange offer that if consummated would result in any person beneficially owning 15% or more of the Issuer Common Shares or any class of equity or voting securities of its subsidiaries whose assets, individually or in the aggregate, constitute 15% or more of the consolidated assets of the Issuer and its subsidiaries as determined on a book-value basis.

The foregoing summaries of the Merger Agreement and the Voting Agreement do not purport to be complete and are qualified in their entirety by reference to the complete text of such agreements attached hereto as Exhibits 1 and 2, respectively. Other than as described above, the Reporting Persons do not currently have any plans or proposals which relate to, or may result in, any of the matters listed in Items 4(a)-(j) of Schedule 13D (although the Reporting Persons reserve the right to develop such plans).

Item 5. Interest in Securities of the Issuer

(a) and (b) The information contained on the cover pages to this Schedule 13D and the information set forth or incorporated in Items 2, 3, 4 and 6 thereof are incorporated herein by reference. Immediately prior to the execution of the Voting Agreement, the Reporting Persons did not beneficially own any Issuer Common Shares. However, upon execution of the Voting Agreement as of July 6, 2011, under the definition of “beneficial ownership” as set forth in Rule 13d-3 under the Exchange Act, each Reporting Person may be deemed to have shared voting power with respect to (and therefore beneficially own) 19,993,429 Issuer Common Shares, representing approximately 37.8% of the Issuer Common Shares outstanding as of April 1, 2011. Accordingly, the percentage of the outstanding Issuer Common Shares that may be deemed to be beneficially owned by each Reporting Person is approximately 37.8%.

Except as set forth above, neither the Reporting Persons nor, to the best of the Reporting Persons’ knowledge, any of the individuals named in Schedule I hereto, has power to vote or to direct the vote or to dispose or direct the disposition of any Issuer Common Shares.

The Reporting Persons disclaim beneficial ownership of any Issuer Common Shares. Neither the filing of this Schedule 13D nor any of its contents shall be deemed to constitute an admission that any Reporting Person is the beneficial owner of the Issuer Common Shares referred to herein for purposes of Section 13(d) of the Exchange Act or for any other purpose, and such beneficial ownership is expressly disclaimed.

(c) Except as set forth in this Item 5, to the best knowledge of the Reporting Persons, neither the Reporting Persons nor any person listed in Schedule I hereof has beneficial ownership of, or has engaged in any transaction during the past 60 days in, any Issuer Common Shares.

(d) Not applicable.

(e) Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

Except as set forth in Item 4 of this Schedule 13D, to the best knowledge of the Reporting Persons, there are no other contracts, arrangements, understandings or relationships (legal or otherwise) among the Reporting Persons and the individuals named in Schedule I and between such persons and any other person with respect to any securities of the Issuer, including, but not limited to, transfer or voting of any securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or losses, or the giving or withholding of proxies.

Item 7. Material to be Filed as Exhibits

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: July 18, 2011

SCHEDULE I

The names and titles of the executive officers of Blackhawk Acquisition Parent, LLC and their present principal occupations and residence or business addresses are set forth below. Each occupation set forth opposite an individual’s name refers to Blackhawk Acquisition Parent, LLC and each individual is a United States citizen.

The names and titles of the executive officers of OEP Parent LLC and their present principal occupations and residence or business addresses are set forth below. Each occupation set forth opposite an individual’s name refers to OEP Parent, LLC and each individual is a United States citizen except Christopher von Hugo who is a citizen of Germany.

The names of the directors and the names and titles of the executive officers of OEP Holding Corporation and their present principal occupations and residence or business addresses are set forth below. Each occupation set forth opposite an individual’s name refers to OEP Holding Corporation and each individual is a United States citizen except Christopher von Hugo who is a citizen of Germany.

The names of the directors and the names and titles of the executive officers of JPMorgan Capital Corporation and their present principal occupations and residence or business addresses are set forth below. Each occupation set forth opposite an individual’s name refers to JPMorgan Capital Corporation and each individual is a United States citizen.

The names and titles of the executive officers of Banc One Financial LLC and their present principal occupations and residence or business addresses are set forth below. Each occupation set forth opposite an individual’s name refers to Banc One Financial LLC and each individual is a United States citizen.

The names of the directors and the names and titles of the executive officers of JPMorgan Chase & Co. and their present principal occupations and residence or business addresses are set forth below. Each occupation set forth opposite an individual’s name refers to JPMorgan Chase & Co., unless otherwise noted, and each individual is a United States citizen.

INDEX TO EXHIBITS

Exhibit 1

JOINT FILING AGREEMENT

Dated as of July 18, 2011

In accordance with Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended, each of the undersigned hereby agrees to the joint filing on behalf of each of the undersigned of a Schedule 13D (including any and all amendments thereto) with respect to the common shares, par value $0.01 per share, of APAC Customer Services, Inc., an Illinois corporation, and that this Joint Filing Agreement may be included as an Exhibit to such joint filing.

This Joint Filing Agreement may be executed in any number of counterparts, all of which together shall constitute one and the same instrument.

[Rest of page intentionally left blank]

IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing Agreement as of the date first written above.

[Signature Page to Joint Filing Agreement]

Exhibit 3

EXECUTION VERSION

VOTING AGREEMENT

This Voting Agreement (this “Voting Agreement”) is entered into as of July 6, 2011, by and among Blackhawk Acquisition Parent, LLC, a Delaware limited liability company (“Parent”) and the undersigned shareholders (collectively, the “Shareholders” and each individually, the “Shareholder”) of APAC Customer Services, Inc., an Illinois corporation (the “Company”). Defined terms used but not defined herein shall have the meanings set forth in the Agreement and Plan of Merger (the “Merger Agreement”), dated as of the date hereof, by and among Parent, Blackhawk Merger Sub, Inc., an Illinois corporation and wholly owned subsidiary of Parent (“Acquisition Sub”), and the Company.

WITNESSETH:

WHEREAS, as of the date hereof, each Shareholder “beneficially owns” (as such term is defined in Rule 13d-3 promulgated under the Exchange Act) (including entitlement to dispose of (or to direct the disposition of) and has the right to vote (or to direct the voting of)) the number of common shares, par value $0.01 per share (the “Company Shares”), of the Company set forth opposite the name of such Shareholder on Schedule I hereto (such Company Shares, together with any other Company Shares the voting power over which is directly or indirectly acquired by such Shareholder until the termination of this Agreement pursuant to the terms hereof, are collectively referred to herein as the “Shareholder Owned Shares”);

WHEREAS, simultaneously herewith, Parent, Acquisition Sub and the Company are entering into the Merger Agreement, pursuant to which Acquisition Sub will merge with and into the Company, with the Company surviving as a wholly owned subsidiary of Parent (the “Merger”);

WHEREAS, the Company’s Board of Directors, in approving the Merger and the Merger Agreement, also approved the execution, delivery and performance of this Agreement by the parties hereto, such that the provisions of Section 7.85 and 11.75 of the IBCA are inapplicable to the execution, delivery and performance of this Agreement by the parties hereto; and

WHEREAS, as a condition to the willingness of Parent to enter into the Merger Agreement, and as an inducement and in consideration therefor, each Shareholder is executing this Agreement;

NOW, THEREFORE, in consideration of the foregoing and the mutual promises, representations, warranties, covenants and agreements contained herein, the parties hereto, intending to be legally bound, hereby agree as follows:

ARTICLE I

DEFINITIONS

Section 1.1 Other Definitions. For purposes of this Agreement:

(a) “Affiliate” means, with respect to any specified Person, any Person that directly, or indirectly through one or more intermediaries, controls, or is controlled by, or is

under common control with, the Person specified. For the purposes of this Agreement, neither the Company nor any of its Subsidiaries shall be deemed to be an Affiliate or Subsidiary of any Shareholder.

(b) “Permitted Transferee” means, with respect to any Shareholder (including any Permitted Transferee), any other Shareholder, any immediate family member of any Shareholder, any trust, partnership, corporation, limited liability company or other entity of which the beneficiaries or beneficial owners, as the case may be, are Shareholders or Permitted Transferees, a trust or other entity for the benefit of any Person that is qualified as a charitable organization under Section 501(c)(3) of the Code, or a family foundation established by or on behalf of one or more of the Shareholders for the purpose of making charitable gifts or donations to Persons that are qualified as charitable organizations under Section 501(c)(3) of the Code.

(c) “Person” means an individual, corporation, limited liability company, general or limited partnership, association, trust, unincorporated organization, other entity or group.

(d) “Representative” means, with respect to any Person, any director, officer, other employee, accountant, consultant, legal counsel, financial advisor, advisor, advisor, agent or other representative of such Person. For the purposes of this Agreement, none of the Representatives of the Company or any of its Subsidiaries shall be deemed to be a Representative of any Shareholder.

ARTICLE II

VOTING AGREEMENT AND GRANT OF IRREVOCABLE PROXY

Section 2.1 Agreement to Vote the Shareholder Owned Shares.

(a) From and after the date hereof, at any meeting of the Company’s shareholders (or any adjournment or postponement thereof), however called, each Shareholder shall vote (or cause to be voted) in person or by proxy all of such Shareholder’s Shareholder Owned Shares:

(i) in favor of the adoption and approval of the Merger Agreement and all of the transactions contemplated by the Merger Agreement, including the Merger (and in favor of any actions and proposals required, or submitted for approval at any meeting of the Company shareholders, in furtherance thereof);

(ii) against any proposal presented to the Company’s Shareholders for approval at any meeting of the Company’s Shareholders, or any written consent in lieu thereof, if the action, transaction or agreement that is the subject of such proposal, following approval by the Company’s Shareholders would reasonably be expected, directly or indirectly, to result in a breach by the Company of any covenant, representation, warranty or other obligations of the Company set forth in the Merger Agreement; and

(iii) against the following actions or proposals (other than the transactions contemplated by the Merger Agreement): (A) any Competing Proposal; (B) any

nominee for election to the Company’s Board of Directors other than (x) a Person nominated by the Company’s Board of Directors or any committee thereof and/or (y) Theodore G. Schwartz; or (C) any other action or proposal to be voted upon by the Company’s shareholders at any meeting of the Company’s shareholders, or any written consent in lieu thereof, if such action or proposal would reasonably be expected, to prevent, impede, interfere with, delay, postpone or adversely affect the transactions contemplated by the Merger Agreement.

(b) Each Shareholder agrees not to enter into any agreement or commitment with any Person the effect of which would violate or be inconsistent with the provisions and agreements set forth in this Article II.

Section 2.2 Irrevocable Proxy.

(a) In furtherance of the Shareholders’ agreements in Section 2.1 of this Agreement, each Shareholder hereby appoints Parent and Parent’s designees, and each of them individually, as such Shareholder’s proxy and attorney-in-fact (with full power of substitution), for and in the name, place and stead of such Shareholder, to vote all Shareholder Owned Shares owned by such Shareholder (at any meeting of the Company’s shareholders (or any adjournment or postponement thereof), however called), or to execute one or more written consents in respect of such Shareholder Owned Shares with respect to the matters described in Section 2.1(a) of this Agreement. If any Shareholder fails for any reason to be counted as present or to vote (including by written consent, if applicable) such Shareholder’s Shareholder Owned Shares in accordance with the requirements of Section 2.1(a) above, then Parent shall have the right to cause to be present or vote such Shareholder’s Shareholder Owned Shares in accordance with the provisions of Section 2.1(a).

(b) Such proxy shall (A) be valid and irrevocable until the valid termination of this Agreement in accordance with (or as otherwise provided in) Article VI hereof and (B) automatically terminate upon the valid termination of this Agreement in accordance with (or as otherwise provided in) Article VI hereof. Each Shareholder represents that any and all other proxies and powers of attorney heretofore given in respect of such Shareholder Owned Shares owned by such Shareholder are revocable, and that such other proxies have been revoked. Each Shareholder affirms that the foregoing proxy is: (x) given (I) in connection with the execution of the Merger Agreement and (II) to secure the performance of such Shareholder’s duties under this Agreement, (y) coupled with an interest and may not be revoked except as otherwise provided in this Agreement and (z) intended to be irrevocable prior to valid termination of this Agreement or as otherwise provided in Article VI hereof. All authority herein conferred shall survive the death or incapacity of such Shareholder and shall be binding upon the heirs, estate, administrators, personal representatives, successors and assigns of such Shareholder. Subject to the other terms and provisions of this Agreement, each Shareholder shall retain the right to vote all of such Shareholder’s Shareholder Owned Shares on all matters not described in Section 2.1(a).

ARTICLE III

STANDSTILL AND NON-SOLICITATION IN RESPECT OF SHAREHOLDER

OWNED SHARES

Section 3.1 Standstill in Respect of Shareholder Owned Shares

Each Shareholder hereby agrees that, from and after the date hereof until the earlier of the Effective Time of the Merger and the valid termination of the Merger Agreement, such Shareholder shall not, directly or indirectly, unless (i) specifically requested by Parent in writing or (ii) expressly contemplated by the terms of this Agreement or the Merger Agreement:

(a) sell, transfer, tender, pledge, encumber, assign or otherwise dispose of (collectively, a “Transfer”), or enter into any contract, option or other agreement with respect to, or consent to, a Transfer of, any or all of the Shareholder Owned Shares; provided that this Section 3.1(a) shall not limit or preclude any Shareholder’s right to Transfer any Shareholder Owned Shares to any Permitted Transferee solely for estate planning or charitable purposes, provided that, (i) the Shareholder provides at least three Business Days advance written notice to Parent of such proposed transfer (including providing such other information and documentation related to the proposed Permitted Transferee as Parent may reasonably request) and (ii) such Permitted Transferee agrees in a written agreement with Parent (in form and substance satisfactory to Parent, in its reasonable discretion) to hold such Shareholder Owned Shares pursuant to, and to be bound by, the terms and conditions of this Agreement as a “Shareholder” hereunder, and to make each of the representations and warranties (which may be made in reliance upon a certificate from the Shareholder) hereunder in respect of the Shareholder Owned Shares transferred as such Shareholder shall have made hereunder (the “Joinder”) and (iii) the Joinder shall be valid and binding in all respects on the Permitted Transferee; provided, further, in the event that any proposed Permitted Transferee does not comply with the obligations imposed hereunder with respect to the Shareholder Owned Shares purported to be transferred to such Person, such transfer shall be deemed null and void ab initio;

(b) acquire, offer to acquire, or agree to acquire, directly or indirectly, by purchase or otherwise, any material assets of the Company or any subsidiary or division thereof;

(c) make, or in any way participate in, directly or indirectly, any “solicitation” of “proxies” (as such terms are used in the rules of the Securities and Exchange Commission) to vote, or otherwise take any action intended to advise or influence any Person with respect to the voting of, any voting securities of the Company, other than in support of the Merger and the Merger Agreement;

(d) make any public announcement with respect to, or submit a proposal for, or offer for (with or without conditions) any extraordinary transaction involving the Company or its securities or material assets;

(e) form, join or in any way participate in a “group” (as defined in Section 13(d)(3) under the Exchange Act) in connection with any of the foregoing;

(f) seek, in any way which may be reasonably likely to require, involve or trigger public disclosure of such request pursuant to applicable Law, to have any provision of this Section 3.1 amended, modified or waived; or

(g) otherwise take, directly or indirectly, any actions with the purpose of avoiding or circumventing any provision of this Section 3.1 or which would reasonably be expected to have the effect of preventing, impeding, interfering with or adversely affecting the consummation of the transactions contemplated by the Merger Agreement or its ability to perform the Shareholder’s obligations under this Agreement.

Any action taken in violation of the foregoing shall be null and void ab initio.

Section 3.2 Dividends, Distributions, Etc. in Respect of Shareholder Owned Shares; Additional Shareholder Owned Shares. In the event of a share dividend or share distribution, or any change in the Company Shares by reason of any share dividend or share distribution, split-up, recapitalization, combination, exchange of shares or the like, the term “Shareholder Owned Shares” shall be deemed to refer to and include the Shareholder Owned Shares as well as all such share dividends and share distributions and any securities into which or for which any or all of the Shareholder Owned Shares may be changed or exchanged or which are received in such transaction. Each Shareholder hereby agrees, during the term of this Agreement, to promptly notify Parent of any new Common Shares acquired by such Shareholder, if any, after the execution of this Agreement. Any such Common Shares shall be subject to the terms of this Agreement as though owned by such Shareholder on the date of this Agreement.

Section 3.3 Competing Proposals in Respect of Shareholder Owned Shares.

(a) Each Shareholder shall not, and shall use his or its reasonable best efforts to ensure that each of his or its Representatives and Affiliates do not, directly or indirectly: (i) solicit or initiate, or knowingly facilitate or encourage (including by way of providing information), any inquiries, proposals or offers that constitute, or that would reasonably be expected to lead to, a Competing Proposal; (ii) participate in any negotiations regarding, or furnish to any person (other than the Company, any other Shareholder or any Representatives of the Shareholder, the Company or any other Shareholder) any nonpublic information with respect to, any Competing Proposal; or (iii) engage in discussions with any person (other than the Company, any other Shareholder or any Representatives of the Shareholder, the Company or any other Shareholder) with respect to any Competing Proposal.

(b) If a Shareholder, or any of his or its Representatives, at any time during the Pre-Closing Period, receives any inquiry regarding a Competing Proposal from a potential bidder or its Representatives, or any potential bidder or its Representatives seeks to initiate negotiations or discussions with the Shareholder related to a Competing Proposal, then such Shareholder shall promptly: (i) advise the Company in writing of such Competing Proposal, inquiry or request (including the identity of the Person making or submitting such Competing Proposal, inquiry or request and the material terms and conditions thereof); and (ii) provide the Company with copies of all documents and other written communications received by such Shareholder setting forth the terms and conditions of such Competing Proposal, inquiry or request.

(c) Each Shareholder shall, and shall ensure that each of his or its Representatives and Affiliates (if applicable), immediately cease and cause to be terminated any existing solicitation by such Shareholder, his or its Representatives or Affiliates of, or discussions or negotiations between such Shareholder, his or its Representatives or Affiliates and, any Person relating to any Competing Proposal.

(d) Each Shareholder agrees that it will promptly inform each of his or its Representatives and his or its Affiliates’ Representatives of the obligations undertaken in this Article III.

ARTICLE IV

REPRESENTATIONS AND WARRANTIES OF THE SHAREHOLDERS

Each Shareholder hereby represents and warrants to Parent as follows:

Section 4.1 Binding Nature of Agreement. This Agreement has been duly and validly executed and delivered by such Shareholder and, assuming that this Agreement constitutes the valid and binding agreement of Parent, constitutes the valid and binding agreement of such Shareholder, enforceable against such Shareholder in accordance with its terms, except that such enforceability may be limited by (i) bankruptcy, insolvency, reorganization, moratorium or other similar Laws now or hereafter in effect relating to creditors’ rights generally, and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding in equity or at law).

Section 4.2 Ownership of Shares. As of the date hereof, such Shareholder beneficially owns the number of Company Shares set forth opposite the name of such Shareholder on Schedule I hereto. Such Shareholder has the sole power to vote (or cause to be voted) such Company Shares and has good and valid title to such Company Shares, free and clear of any and all pledges, mortgages, liens, charges, proxies, voting agreements, encumbrances, adverse claims, options, security interests and demands of any nature or kind whatsoever, other than those created by this Agreement.

Section 4.3 No Conflicts. Neither the execution and delivery of this Agreement by such Shareholder, nor the consummation by such Shareholder of the transactions contemplated hereby, will result in, or give rise to, a violation or breach of or a default under any of the terms of any material contract, understanding, agreement or other instrument or obligation to which such Shareholder is a party or by which such Shareholder or any of the Shareholder Owned Shares owned by such Shareholder or such Shareholder’s assets may be bound, or (ii) violate any applicable Law, except, with respect to any of the foregoing clauses (i) and (ii), as does not and would not reasonably be expected to impair such Shareholder’s ability to perform his or its obligations under this Agreement.

Section 4.4 Reliance by Parent. Such Shareholder understands and acknowledges that Parent is entering into the Merger Agreement in reliance upon such Shareholder’s execution and delivery of this Agreement and the representations and warranties of such Shareholder contained

herein. Such Shareholder understands and acknowledges that the Merger Agreement governs the terms of the Merger and the other transactions contemplated thereby.

Each Shareholder that is a non-natural person further represents and warrants to Parent as follows:

Section 4.5 Corporate Organization. Each Shareholder is duly organized, validly existing and in good standing under the Laws of its jurisdiction of formation.

Section 4.6 Authority Relative to This Agreement. Each Shareholder has the requisite corporate power and authority to execute and deliver this Agreement and to consummate the transactions contemplated hereby. This Agreement and the consummation by each Shareholder of the transactions contemplated hereby have been duly and validly authorized by the board of directors, general partner or similar governing body of each Shareholder, and no other corporate proceedings on the part of each Shareholder are necessary to authorize this Agreement or to consummate the transactions contemplated hereby.

Section 4.7 No Conflicts. Neither the execution and delivery of this Agreement by each Shareholder, nor the consummation by such Shareholder of the transactions contemplated hereby, will conflict with or result in any breach of the organizational documents of such Shareholder.

ARTICLE V

REPRESENTATIONS AND WARRANTIES OF PARENT

Parent hereby represents and warrants to the Shareholders as follows:

Section 5.1 Corporate Organization. Parent is a corporation duly organized, validly existing and in good standing under the Laws of its jurisdiction of incorporation.

Section 5.2 Authority Relative to This Agreement. Parent has the requisite corporate power and authority to execute and deliver this Agreement and to consummate the transactions contemplated hereby. This Agreement and the consummation by Parent of the transactions contemplated hereby have been duly and validly authorized by the board of directors of Parent, and no other corporate proceedings on the part of Parent are necessary to authorize this Agreement or to consummate the transactions contemplated hereby. This Agreement has been duly and validly executed and delivered by Parent and, assuming that this Agreement constitutes the valid and binding agreement of the Shareholder, constitutes the valid and binding agreement of Parent, enforceable against Parent in accordance with its terms, except that such enforceability may be limited by (i) bankruptcy, insolvency, reorganization, moratorium or other similar Laws now or hereafter in effect relating to creditors’ rights generally, and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding in equity or at law).

Section 5.3 No Conflicts. Neither the execution and delivery of this Agreement by Parent, nor the consummation by Parent of the transactions contemplated hereby, will (i) conflict with or result in any breach of the governing documents of Parent; (ii) require any Permit from any Governmental Authority; (iii) result in, or give rise to, a violation or breach of or a default

under any of the terms of any material contract, understanding, agreement or other instrument or obligation to which Parent is a party, or (iv) violate any applicable Law, except, with respect to any of the foregoing clauses (i) through (iv), as does not and could not reasonably be expected to impair Parent’s ability to perform its obligations under this Agreement.

ARTICLE VI

TERMINATION

Section 6.1 Termination.

(a) Subject to Section 6.1(b), this Agreement shall terminate, without further action by any of the parties hereto, and none of Parent or any of the Shareholders shall have any rights or obligations under this Agreement, immediately upon the earliest to occur of: (i) the termination of this Agreement by mutual written consent of Parent and the Shareholders, (ii) the termination of the Merger Agreement in accordance with its terms, (iii) February 29, 2012, (iv) any reduction in or change in the form of the Merger Consideration and (v) the Effective Time of the Merger.

(b) Notwithstanding Section 6.1(a), (i) termination of this Agreement shall not prevent any party hereunder from seeking any remedies (at law or in equity) against any other party hereto for such party’s willful breach of any of the terms of this Agreement prior to the termination of this Agreement.

ARTICLE VII

MISCELLANEOUS

Section 7.1 Appraisal Rights. To the extent permitted by applicable Law, each Shareholder hereby waives and agrees not to exercise any rights of appraisal or rights to dissent from the Merger that he or she may have under applicable Law.

Section 7.2 Documentation and Information. Each Shareholder (i) consents to and authorizes the publication and disclosure by Parent of its identity and holdings of the Shareholder Owned Shares and the nature of such Shareholders’ commitments, arrangements and understandings under this Agreement, in any press release, the Proxy Statement or any other disclosure document required in connection with the Merger or any transactions contemplated by the Merger Agreement, and (ii) will use its or his reasonable best efforts to give to Parent, as promptly as practicable, any information reasonably related to the foregoing as it may reasonably require for the preparation of any such disclosure documents. Each Shareholder will use its or his reasonable best efforts to notify Parent, as promptly as practicable, of any required corrections with respect to any written information supplied by such Shareholder specifically for use in any such disclosure document, if and to the extent such Shareholder becomes aware that any such information has become false or misleading in any material respect.

Section 7.3 Further Actions. Each of the parties hereto agrees that it, he or she will use its, his or its reasonable best efforts to do all things reasonably necessary to effectuate this Agreement.

Section 7.4 Waivers. No failure on the part of any party to exercise any power, right, privilege or remedy under this Agreement, and no delay on the part of any party in exercising any power, right, privilege or remedy under this Agreement, shall operate as a waiver of such power, right, privilege or remedy; and no single or partial exercise of any such power, right, privilege or remedy shall preclude any other or further exercise thereof or of any other power, right, privilege or remedy. No party shall be deemed to have waived any claim arising out of this Agreement, or any power, right, privilege or remedy under this Agreement, unless the waiver of such claim, power, right, privilege or remedy is expressly set forth in a written instrument duly executed and delivered on behalf of such party; and any such waiver shall not be applicable or have any effect except in the specific instance in which it is given.

Section 7.5 Counterparts. This Agreement may be executed and delivered (including by facsimile transmission or by e-mail of a .pdf attachment) in two (2) or more counterparts, and by the different parties hereto in separate counterparts, each of which when executed and delivered shall be deemed to be an original but all of which taken together shall constitute one and the same agreement.

Section 7.6 Applicable Law; Jurisdiction; Waiver of Jury Trial. This Agreement shall be governed by, and construed and enforced in accordance with, the laws of the State of Illinois, regardless of the laws that might otherwise govern under applicable principles of conflicts of laws thereof In any action between any of the parties arising out of or relating to this Agreement or any of the transactions contemplated by this Agreement, each of the parties: (a) irrevocably and unconditionally consents and submits to the exclusive jurisdiction and venue of a court of the State of Illinois located in Cook Country, Illinois (unless the federal courts have exclusive jurisdiction over the matter, in which case each of the parties irrevocably and unconditionally consents and submits to the jurisdiction of a federal court sitting in Cook County in the State of Illinois); (b) agrees that it, he or she will not attempt to deny or defeat such jurisdiction by motion or other request for leave from such court; and (c) agrees that it, he or she will not bring any such action in a court of the State of Illinois located in Cook Country, Illinois (unless the federal courts have exclusive jurisdiction over the matter, in which case each of the parties agrees that it will not bring such action in any court other than a Federal court sitting in Cook County in the State of Illinois). Service of any process, summons, notice or document to any party’s address and in the manner set forth in Section 7.6 shall be effective service of process for any such action. EACH PARTY HEREBY IRREVOCABLY WAIVES TO THE FULLEST EXTENT PERMITTED BY LAW ANY RIGHT IT, HE OR SHE MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY ACTION, PROCEEDING OR COUNTERCLAIM (WHETHER BASED ON CONTRACT, TORT, EQUITY OR OTHERWISE) ARISING OUT OF OR RELATING TO THIS AGREEMENT OR ANY OF THE TRANSACTIONS CONTEMPLATED BY THIS AGREEMENT, IN EACH CASE, WHETHER NOW EXISTING OR HEREAFTER ARISING.

Section 7.7 Notices. Any notice required to be given hereunder shall be sufficient if in writing, and sent by facsimile transmission or e-mail of a .pdf attachment (provided that any notice received by facsimile or e-mail transmission or otherwise at the addressee’s location on any Business Day after 5:00 p.m. (addressee’s local time) shall be deemed to have been received at 9:00 a.m. (addressee’s local time) on the next Business Day), by reliable overnight delivery service (with proof of service), hand delivery or certified or registered mail (return receipt

requested and first-class postage prepaid), addressed as follows (or at such other address for a party as shall be specified in a notice given in accordance with this Section 7.7):

If to Parent to:

Blackhawk Acquisition Parent, LLC

c/o One Equity Partners IV, L.P.

320 Park Avenue

New York, New York 10022

Attention: Judah A. Shechter

Telephone: (212) 270-7689

Facsimile No.: (917) 464-7716

with a copy to:

Dechert LLP

1095 Avenue of the Americas

New York, New York 10036

Attention: Derek Winokur, Esq.

(212) 698-3500

Facsimile No. (212) 698-3599

If to the Shareholders, to:

c/o APAC Customer Services, Inc.

2201 Waukegan Road, Suite 300

Bannockburn, IL 60015

Attention: General Counsel

Telephone: (847) 236-5452

Facsimile No.: (847) 236-5451

with a copy to:

Katten Muchin Rosenman LLP

525 W. Monroe Street

Chicago, Illinois 60661

Attention: Jeffrey R. Patt

Telephone: (312) 902-5604

Facsimile No.: (312) 577-8864

Section 7.8 Entire Agreement; Assignment; Third Party Beneficiaries. This Agreement constitutes the entire agreement and supersedes all prior agreements and understandings, both written and oral, or between the parties with respect to the subject matter hereof. This Agreement shall be binding upon, and shall be enforceable by and inure solely to the benefit of, the parties hereto and their respective successors and permitted assigns; provided, however, that neither this Agreement nor any of the parties’ rights, interests or obligations hereunder may be assigned or delegated, in whole or in part, by operation of law or otherwise,

without the prior written consent of the other party, and any attempted assignment or delegation of this Agreement or any of such rights, interests or obligations by any party without the other parties’ prior written consent shall be void and of no effect; provided, however, that Parent may assign this Agreement to an Affiliate thereof (including, for the avoidance of doubt, NCO Group, Inc.), so long as such assignment does not result in (a) any greater liability than any Shareholder would otherwise have had, or (b) any breach by Parent of any of its obligations under this Agreement; provided that, upon such assignment, Parent shall remain jointly and severally liable with its applicable Affiliate to the Shareholders for performing all of its obligations hereunder. Nothing in this Agreement, express or implied, is intended to or shall confer upon any Person (other than the parties hereto) any right, benefit or remedy of any nature. This Agreement is intended to create a contractual relationship between the Shareholder, on the one hand, and Parent, on the other hand, and is not intended to create, and does not create, any agency, partnership, joint venture or any like relationship among the parties hereto. Without limiting the generality of the foregoing, neither the Shareholder nor Parent, by entering into this Agreement, intends to form a “group” for purposes of Rule 13d-5(b)(1) of the Exchange Act or any other similar provision of applicable Law with Parent or any other shareholder of the Company.

Section 7.9 Severability. If any term or provision of this Agreement is held by a court of competent jurisdiction or Governmental Authority to be invalid, void or unenforceable in any situation in any jurisdiction, such holding shall not affect the validity or enforceability of the remaining terms and provisions of this Agreement or the validity or enforceability or application of the invalid or unenforceable term or provision in any other situation or in any other jurisdiction. If a final judgment of a court of competent jurisdiction declares that any term or provision of this Agreement is invalid or unenforceable, the parties hereto agree that the court making such determination shall have the power to limit such term or provision, to delete specific words or phrases or to replace such term or provision with a suitable and equitable term or provision that is valid and enforceable and that comes closest to expressing the intention of the invalid or unenforceable term or provision, and this Agreement shall be valid and enforceable as so modified. In the event such court does not exercise the power granted to it in the prior sentence, the parties hereto agree to replace such invalid or unenforceable term or provision with a valid and enforceable term or provision that will achieve, to the extent possible, the economic, business and other purposes of such invalid or unenforceable term or provision.

Section 7.10 Certain Interpretations. For purposes of this Agreement:

(a) Unless otherwise specified, all references in this Agreement to Articles and Sections shall be deemed to refer to Articles and Sections of this Agreement.

(b) The Article and Section captions herein are for convenience of reference only, do not constitute part of this Agreement and shall not be deemed to limit or otherwise affect any of the provisions hereof.

(c) Unless the context otherwise requires, words describing the singular number shall include the plural and vice versa, and words denoting any gender shall include all genders.

(d) The words “include,” “includes” and “including,” when used herein shall be deemed in each case to be followed by the words “without limitation.”

(e) The parties hereto agree that they have been represented by legal counsel during the negotiation and execution of this Agreement and, therefore, waive the application of any Law, regulation, holding or rule of construction providing that ambiguities in an agreement or other document shall be construed against the party drafting such agreement or document.

Section 7.11 Fees and Expenses. Except as otherwise provided herein, whether or not the Merger is consummated, all costs and expenses incurred in connection with this Agreement and the transactions contemplated hereby shall be paid by the party incurring such costs and expenses.

Section 7.12 Ownership Interest. Nothing contained in this Agreement shall be deemed to vest in Parent any direct or indirect ownership or incidence of ownership of or with respect to any Shareholder Owned Shares. All rights, ownership and economic benefits of and relating to the Shareholder Owned Shares shall remain vested in and belong to the Shareholders, and Parent shall have no authority to direct the Shareholders in the voting or disposition of any of the Shareholder Owned Shares, except as otherwise provided in this Agreement.

Section 7.13 Capacity as a Shareholder. Parent acknowledges that each Shareholder has entered into this Agreement solely in his or its capacity as the record and/or beneficial owner of Company Shares (and not in capacity as a director or officer of the Company or any of its subsidiaries) and, notwithstanding anything to the contrary herein, nothing herein shall limit or affect any Shareholder who serves as a director or officer of the Company or any of its subsidiaries in acting in his or its capacity as a director or officer of the Company or any such subsidiaries, nor shall it limit or affect any Representative or Affiliate of the Company or of any of the Company’s subsidiaries.

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IN WITNESS WHEREOF, Parent and the Shareholders have caused this Agreement to be duly executed as of the day and year first above written.

EXECUTION VERSION

Schedule I

Shareholder Owned Shares