Page 1 of 3 - -------- U.S. SECURITIES AND EXCHANGE COMMISSION FORM 4 WASHINGTON, D.C. 20549 - -------- / / CHECK THIS BOX IF NO STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP LONGER SUBJECT TO SECTION 16. FORM 4 OR Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, FORM 5 OBLIGATIONS MAY Section 17(a) of the Public Utility Holding Company Act of 1935 or CONTINUE. SEE Section 30(f) of the Investment Company Act of 1940 INSTRUCTION 1(b). (Print or Type Responses) - ------------------------------------------------------------------------------------------------------------------------------------ 1. Name and Address of Reporting Person* 2. Issuer Name AND Ticker or Trading Symbol 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Mack William L. Mack-Cali Realty Corporation (CLI) ---- ---- - --------------------------------------------------------------------------------------------- Officer (give Other (Last) (First) (Middle) 3. IRS or Social Security 4. Statement for ---- title ---- (specify Number of Reporting Month/Year below) below) Person (Voluntary) ----------------- ------------------ c/o Mack-Cali Realty Corporation 05/02 11 Commerce Drive - -------------------------------------------- --------------------- 7. Individual or Joint/Group Filing (Street) 5. If Amendment, (Check Applicable Line) Date of Original X Form filed by One Reporting Person (Month/Year) --- Form filed by More than One Cranford, New Jersey 07016 --- Reporting Person - ------------------------------------------------------------------------------------------------------------------------------------ (City) (State) (Zip) TABLE I - NON-DERIVATIVE SECURITIES ACQUIRED, DISPOSED OF, OR BENEFICIALLY OWNED - ------------------------------------------------------------------------------------------------------------------------------------ 1. Title of Security 2. Trans- 3. Trans- 4. Securities Acquired (A) 5. Amount of 6. Owner- 7. Nature (Instr. 3) action action or Disposed of (D) Securities ship of In- Date Code (Instr. 3, 4 and 5) Beneficially Form: direct (Instr. 8) Owned at Direct Bene- (Month/ End of (D) or ficial Day/ ------------------------------------------- Month Indirect Owner- Year) (A) or (I) ship Code V Amount (D) Price (Instr. 3 (Instr. 4) (Instr. 4) and 4) - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ * If the form is filed by more than one reporting person, SEE Instruction 4(b)(v). Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. (Over) (Print or Type Responses)

Page 2 of 3 FORM 4 (CONTINUED) TABLE II - DERIVATIVE SECURITIES ACQUIRED, DISPOSED OF, OR BENEFICIALLY OWNED (E.G., PUTS, CALLS, WARRANTS, OPTIONS, CONVERTIBLE SECURITIES) - ------------------------------------------------------------------------------------------------------------------------ 1. Title of Derivative Security 2. Conver- 3. Trans- 4. Transac- 5. Number of Deriv- 6. Date Exer- (Instr. 3) sion or action tion Code ative Securities Ac- cisable and Ex- Exercise Date (Instr. 8) quired (A) or Dis- piration Date Price of (Month/ posed of (D) (Month/Day/ Deriv- Day/ (Instr. 3, 4, and 5) Year) ative Year) Security ----------------------------------------------------------- Code V (A) (D) Date Expira- Exer- tion cisable Date - ------------------------------------------------------------------------------------------------------------------------ Units of Limited 5/8/02 J(2) 11,905 (1) Partnership Interest (1) - ------------------------------------------------------------------------------------------------------------------------ Units of Limited 5/8/02 J(2) 123,425 (1) Partnership Interest (1) - ------------------------------------------------------------------------------------------------------------------------ Series B Preferred Units 5/8/02 J(2) 755 (4) of Limited Partnership Interest (4) - ------------------------------------------------------------------------------------------------------------------------ Series B Preferred Units 5/8/02 J(2) 7,844 (4) of Limited Partnership Interest (4) - ------------------------------------------------------------------------------------------------------------------------ Warrants to Purchase Units 5/8/02 J(2) 6,109 (6) of Limited Partnership Interest (6) - ------------------------------------------------------------------------------------------------------------------------ Warrants to Purchase Units 5/8/02 J(2) 63,334 (6) of Limited Partnership Interest (6) - ------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------ 7. Title and Amount of Under- 8. Price 9. Number 10. Owner- 11. Nature lying Securities of of Deriv- ship of In- (Instr. 3 and 4) Deriv- ative Form direct ative Securi- of De- Bene- Secur- ties rivative ficial ity Bene- Secu- Own- (Instr. ficially rity: ership 5) Owned Direct (Instr. 4) at End (D) or Amount or of Indi- Title Number of Month rect (I) Shares (Instr. 4) (Instr. 4) - ------------------------------------------------------------------------------------------ Common Stock (1) 872,626 (1) D - ------------------------------------------------------------------------------------------ Common Stock (1) 361,265 (1) I (3) - ------------------------------------------------------------------------------------------ Common Stock (4) 54,556 (4) D - ------------------------------------------------------------------------------------------ Common Stock (4) 22,594 (4) I (5) - ------------------------------------------------------------------------------------------ Common Stock (6) 439,477 (6) D - ------------------------------------------------------------------------------------------ Common Stock (6) 182,448 (6) I (7) - ------------------------------------------------------------------------------------------ Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, SEE Instruction 6 for procedure. Page 3 of 3 Explanation of Responses: (1) The units of limited partnership interest ("Units") represent interests in Mack-Cali Realty, L.P., a Delaware limited partnership, through which Mack- Cali Realty Corporation (the "Corporation") conducts its real estate activities. The Units are redeemable for cash, based upon the fair market value of an equivalent number of shares of Common Stock at the time of such redemption, or, at the election of the Corporation, shares of Common Stock on a one-for-one basis. (2) On May 8, 2002, TriWest Associates, LP transferred all of its rights, title and interest in and to its Units, the Series B Preferred Units of limited partnership interest (the "Series B Preferred Units") and Warrants to purchase Units (the "Warrants"). Prior to the transfer, the reporting person possessed sole or shared dispositive power or voting power with respect to all the Units, the Series B Preferred Units and Warrants held by TriWest Associates, LP. (3) Includes Units held by members of the reporting person's immediate family and trusts of which he is a trustee and Units held by trusts of which the reporting person or his wife is a trustee, of which the reporting person disclaims beneficial ownership. (4) The Series B Preferred Units are immediately convertible into Units. Any Units received upon conversion of the Series B Preferred Units shall be redeemable into an equal number of shares of Common Stock. The reporting person's 54,556 Series B Preferred Units are convertible into 1,574,488 Units and the 22,594 Series B Preferred Units held by the reporting person's immediate family and trusts are convertible into 652,063 Units. (5) Includes Series B Preferred Units held by members of the reporting person's immediate family and trusts of which he is a trustee and Series B Preferred Units held by trusts of which the reporting person or his wife is a trustee, of which the reporting person disclaims beneficial ownership. (6) The Warrants are exercisable on a one-for-one basis. The Warrants are exercisable at a price of $37.80 per Unit and expire on December 11, 2002. Any Units received upon exercise of the Warrants shall be immediately redeemable into Common Stock. (7) Includes Warrants held by members of the reporting person's immediate family and trusts of which he is a trustee and Warrants held by trusts of which the reporting person or his wife is a trustee, of which the reporting person disclaims beneficial ownership. ** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. SEE 18 U.S.C. 1001 and 15 U.S.C. 78ff(a). /s/ William L. Mack 6/10/02 ----------------------------------- ----------- **Signature of Reporting Person Date * If the form is filed by more than one reporting person, SEE Instruction 4(b)(v). Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. (Over) (Print or Type Responses)