Mills Estruturas e Serviços de Engenharia S A : Notice to Shareholders - Capital Increase resulting from the exercise of the stock option plan issued by the Company

MILLS ESTRUTURAS E SERVIÇOS DE ENGENHARIA S.A.

CNPJ/MF Nº 27.093.558/0001-15

NIRE 33.3.0028974-7

NOTICE TO SHAREHOLDERS

Mills Announces Capital Increase resulting from the exercise of the stock option plan issued by the Company

Mills Estruturas e Serviços de Engenharia S.A. ("Company"), for the purposes of Appendix 30- XXXII of ICVM 480 of CVM Instruction 481/09, provides the information regarding the capital increase approved by the Company's Board of Directors in the meeting held on May 21st, 2021, as follows:

1. Date of the Shareholders´meeting in which the stock option plan was approved

The Company's General Meeting of Shareholders approved the Stock Option Grant Plan on April 28 th, 2016. The Board of Directors approved the Stock Option Program on May 31, 2016.

2. Value of the capital increase and the new capital stock

The capital stock will be increased in the amount R$686,375.00 (six hundred, eighty-six thousand, three hundred and seventy five reais.

Consequently, the Company's capital stock will increase from R$1,089,649,677.39 (one billion, eighty nine million, six hundred and forty nine thousand, six hundred and seventy seven reais and thirty nine cents) to R$ 1,090,336,052.39 (one billion, ninety million, three hundred and thirty six thousand, fifty two reais and thirty nine cents).

3. Number of shares issued of each type and class

It will be issued 212.500 (two hundred, twelve thousand and five hundred) new nominative common shares, with no par value, which will participate in equal conditions of all the benefits, including dividends and interest on own capital that may be distributed by the Company.

4. Issuance price of the new shares

The Company estimates that the new common shares will be issued at the R$3.21 (three reais and twenty-one cents) per share.

5. Price of each type and class of the issuer´s shares in the markets in which they are traded

1. minimum, average and maximum price in each year for the last three (3) years:

	2018	2019	2020
Minimum	1.70	4.25	3.36
Average	2.99	6.21	6.65
Maximum	4.65	10.45	10.85

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b)	minimum, average and maximum price in each quarter of the year for the last two (2)
years:
		1Q19	2Q19	3Q19	4Q19	1Q20	2Q20		3Q20	4Q20		1Q21
Minimum	4.25	4.39	5.92	6.25	3.86	3.36		5.64	5.08		4.81
Average	5.19	5.03	6.91	7.66	8.39	4.94		6.99	6.23		5.97
Maximum	5.90	6.09	7.82	10.45	10.85	6.14		8.00	7.08		5.16
	c) minimum, average and maximum price in each month for the last six (6) months:
		Nov/20	Dez/20	Jan/21	Fev/21	Mar/21	Abr/21
Minimum	5.09	6.15	5.76	5.31	4.81	6.54
Average	6.05	6.64	6.13	5.96	5.90	7.64
Maximum	6.61	7.08	6.51	5.61	5.16	6.82

1. average price for the last ninety (90) days: R$7.16 - from March 21, 2021 until May 21, 2021.

6. Percentage of potential dilution resulting from the issue

The issue resulting from the capital increase will cause a dilution of 0.08%

Rio de Janeiro, May 21, 2021.

James Oliver Guerreiro Carneiro

CFO and IRO

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