AMG Funds I N-CSR Certified annual shareholder report (management investment company)

CERTIFICATION FILED AS EXHIBIT 12(B) TO FORM N-CSR

Name of Issuer: MANAGERS TRUST I: MANAGERS AMG FQ U.S. EQUITY FUND, MANAGERS AMG FQ TAX-MANAGED U.S. EQUITY FUND, MANAGERS AMG FQ GLOBAL ALTERNATIVES FUND, MANAGERS FREMONT GLOBAL FUND, MANAGERS SMALL CAP FUND, MANAGERS FREMONT MICRO-CAP FUND, MANAGERS FREMONT INSTITUTIONAL MICRO-CAP FUND, MANAGERS REAL ESTATE SECURITIES FUND, MANAGERS FREMONT BOND FUND AND MANAGERS CA INTERMEDIATE TAX-FREE FUND

In connection with the Report on Form N-CSR of the above-named issuer that is accompanied by this certification, the undersigned hereby certifies, to his knowledge, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the issuer.

Dated:	January 6, 2008	/s/ John H. Streur
		John H. Streur President

CERTIFICATION FILED AS EXHIBIT 12(B) TO FORM N-CSR

Name of Issuer: MANAGERS TRUST I: MANAGERS AMG FQ U.S. EQUITY FUND, MANAGERS AMG FQ TAX-MANAGED U.S. EQUITY FUND, MANAGERS AMG FQ GLOBAL ALTERNATIVES FUND, MANAGERS FREMONT GLOBAL FUND, MANAGERS SMALL CAP FUND, MANAGERS FREMONT MICRO-CAP FUND, MANAGERS FREMONT INSTITUTIONAL MICRO-CAP FUND, MANAGERS REAL ESTATE SECURITIES FUND, MANAGERS FREMONT BOND FUND AND MANAGERS CA INTERMEDIATE TAX-FREE FUND

In connection with the Report on Form N-CSR of the above-named issuer that is accompanied by this certification, the undersigned hereby certifies, to his knowledge, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the issuer.

Dated:	January 6, 2008	/s/ Donald S. Rumery
		Donald S. Rumery Chief Financial Officer