Exhibit 10.11

LOGO [g185463g40b71.jpg]

550, 333 – 11 Ave SW

Calgary, AB T2R 1L9

P. +1.403.237.7102

F. +1.403.237.7103

April 29, 2011

TransAtlantic Petroleum Ltd.

5910 N. Central Expressway, Suite 1755

Dallas, Texas 75206

 

Re:

Conditional Offer (the “Conditional Offer”) dated February 8, 2011 between
Valeura Energy Inc., TransAtlantic Petroleum Ltd. and TransAtlantic Worldwide
Ltd., as amended pursuant to letter amending agreements dated March 18,
2011, April 2, 2011, April 15, 2011 and April 23, 2011

This letter agreement will confirm the parties agreement to amend clause 5(a)
and clause 11 of the Conditional Offer by deleting the references therein to
“May 2, 2011” and replacing same with “May 11, 2011”.

Yours truly,

 

VALEURA ENERGY INC.

   

per: /s/ James D. McFarland

   

  President and CEO

     

Accepted and agreed to this 30th day of April, 2011.

 

TRANSATLANTIC PETROLEUM LTD.

 

TRANSATLANTIC WORLDWIDE LTD.

   

per: /s/ Scott C. Larsen

 

per: /s/ Scott C. Larsen