exhibit 10. 43 contract code : cai - 2007 - store - 012 contract of material reserves and sales this contract is made on april 25, 2007 at huatugou, mangya, qinghai, province between : beijing bhd petroleum technology co., ltd. ( the “ seller ” ), a corporation organized and existing under the laws of the prc. phone number : mr. zhiqiang feng : 13897078018 postcode : 710006 and : petrochina qinghai oilfield co., ltd ( the “ buyer ” ), a corporation organized and existing under the laws of the prc. phone number : 0937 # # # - # # # - # # # # # # # - # # # - # # # # postcode : 736202 according to the material purchases tender offer outcome on 2005, the buyer shall render the services of material reserves and sales to the seller. for the purpose of defining the obligations of both parties, we hereby conclude this contract according to the contract law of the people ’ s republic of china. 1. subject matter of the contract : see the accessory form 2. delivery term and quality guarantee period : see the accessory form 3. contract value and the method of payment : 3. 1 contract value : rmb1, 034, 182. 89 ( rmb one million thirty - four thousand one hundred eighty - two point eighty - nine ) 3. 2 method of payment : adopt the method of agential reserves and sales ; determine the name, stipulation and model of the agential reserves and sales material according to the outcome of the tender ; the seller shall, at the sight of the provision notice and within the delivery term, provide the material to the buyer according to the plan which is submitted by the buyer. the seller shall pay the material expense quarterly after making use of them. the seller agrees to remain 5 % out of purchase price as quality guarantee deposit. the guarantee deposit will be collected when the quality guarantee period is complete, and without quality problems. if any quality problems arises during the quality guarantee period and the seller cannot complete the maintenance, there will be no return of this deposit. ( the quality guarantee period will be calculated the first date the buyer starts to use the seller ’ s products. ) 3. 3 on the twenty - fifth date of the last month of each quarter, the seller shall collect the payment with carrying this contract, quality