UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN ISSUER
PURSUANT TO RULE 13a-16 OR 15b-16 OF
THE SECURITIES EXCHANGE ACT OF 1934

For the month of September 2017

Commission File Number 001-35591

GRAÑA Y MONTERO S.A.A.

(Exact name of registrant as specified in its charter)

GRAÑA Y MONTERO GROUP

(Translation of registrant’s name into English)

Republic of Peru

(Jurisdiction of incorporation or organization)

Avenida Paseo de la República 4667, Lima 34,

Surquillo, Lima

Peru

(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:

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): [ ]

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): [ ]

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.

If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): Not applicable.

Messrs.,
Superintendencia del Mercado de Valores – SMV
Present. -

Reference: Relevant Information Communication – Divestment Plan

Dear Sirs:

By means of this letter, we hereby announce, as a Relevant Information Communication on September 27, 2017, our subsidiary NORVIAL SA, through the General Shareholders' Meeting, approved the subscription of Addendum No. 5 to the Concession Agreement of the Ancón-Huacho-Pativilca section of the North Pan-American Highway, between the company and the Peruvian State.

The purpose of this addendum is to: (i) allow the partial reception of the works of the second stage as well as the new and complementary works executed by the company, (ii) enable the execution of the works resulting from the requests for modification of the technical file of the second stage requested by the grantor (Ministry of Transportation and Communications) in accordance with Addendum 4 to the Concession Agreement, and iii) allow the collaboration of the company in specific efforts related to the release of land and interferences.

___________________________
/s/ Claudia Drago Morante
Stock Market Representative
Graña y Montero S.A.A.

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.

GRAÑA Y MONTERO S.A.A.

By: /s/ CLAUDIA DRAGO MORANTE
Name: Claudia Drago Morante
Title: Stock Market Representative
Date: September 27, 2017