JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)

Exhibit 99.6

JOINT FILING AGREEMENT

PURSUANT TO RULE 13d-1(k)

The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The undersigned acknowledge that each will be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained herein and therein, but will not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate.

Date: June 18, 2020	ALFA TELECOM TURKEY LIMITED
	By:		/s/ Xxxxxx Xxxx
	Name:		Xxxxxx Xxxx
	Title:		Director
Date: June 18, 2020	ATTL HOLDINGS (CYPRUS) LTD
	By:		/s/ Xxxx Xxxxx
	Name:		Xxxx Xxxxx
	Title:		Director
Date: June 18, 2020	ATTL HOLDINGS S.À X.X.
	By:		/s/ Xxxxxx Xxxx
	Name:		Xxxxxx Xxxx
	Title:		Manager
Date: June 18, 2020	ATTL HOLDINGS UK LIMITED
	By:		/s/ Xxxxx Xxxxx
	Name:		Xxxxx Xxxxx
	Title:		Director
Date: June 18, 2020	LETTERONE CORE INVESTMENTS S.À X.X.
	By:		/s/ Xxxxxxx Xxxxxxxxx
	Name:		Xxxxxxx Xxxxxxxxx
	Title:		Class I Director
Date: June 18, 2020	LETTERONE INVESTMENT HOLDINGS S.A.
	By:		/s/ Xxxxxx Xxxx
	Name:		Xxxxxx Xxxx
	Title:		Authorized Signatory

Date: June 18, 2020	L1T UB HOLDINGS S.À X.X.
	By:		/s/ Xxxxxx Xxxx
	Name:		Xxxxxx Xxxx
	Title:		Manager
Date: June 18, 2020	INTERNATIONAL MOBILE TELECOM INVESTMENT STICHTING ADMINISTRATIEKANTOOR
	By:		/s/ Xxxxxx Xxxxx Xxxx
	Name:		Xxxxxx Xxxxx Xxxx
	Title:		Director

	By:		/s/ Xxxxx Xxxx
	Name:		Xxxxx Xxxx
	Title:		Director

Date: June 18, 2020	IMTIS HOLDINGS S.À X.X.
	By:		/s/ Xxxxxx Xxxxx Xxxx
	Name:		Xxxxxx Xxxxx Xxxx
	Title:		Manager