EXHIBIT 10.6

STOCK PURCHASE AND ASSET SALE AGREEMENT

This  Agreement  is made  this  1st day of  July,  1999  between  Inter-American
Telecommunications Corporation ("Buyer") and Cognigen Corporation ("Seller").

RECITALS

The Buyer was  organized  for the purpose of  consolidating  the  operations  of
certain  enterprises  engaged in the commerce and  transmission  of domestic and
international  long  distance  telephone  and  related  services.  The Seller is
engaged in direct and multilevel  electronic marketing and sale of long distance
telephone  service  products.  The  Buyer  will be  engaged  in the  direct  and
multilevel  agency  marketing and sale of long distance  service and products as
well as switching  and transport of voice,  fax and data  telephone and Internet
traffic and related services.

In order to promote and bring about greater synergies of effort and economies of
scale, the Buyer has agreed to purchase and the Seller has agreed to sell all of
the assets described herein.

1.       PARTIES:

1.1  Inter-American  Telecommunications  Holding  Corporation,  the Buyer,  also
     referred to as "ITHC," a Delaware  corporation with 10,000 common shares of
     authorized capital stock with no par value.

1.2  Cognigen  Corporation,  the Seller also referred to as "Cognigen," a Nevada
     corporation.

1.3  ITHC  and  Cognigen  are  hereinafter   collectively  referred  to  as  the
     "Parties."

2.       CONSIDERATION:

2.1  The Seller  has agreed to sell,  transfer  and  exchange  all of the herein
     described  assets  owned by it to the Buyer  and the  Buyer  has  agreed to
     purchase those assets for and in consideration of:

     a.   Five Thousand Five Hundred (5,500) shares of the Buyer's common stock,
          and

     b.   Payment of $300,000 cash, and

     c.   A  contract  of  employment  in favor of Kevin  Anderson  as  Managing
          Director of the Cognigen E-Commerce Division of ITHC for a period of 4
          years with an annual base salary of $175,000, and

     d.   Provision of $600,000 of working  capital,  over and above the current
          level of  operating  costs to cover  business  expansion  and staffing
          requirements  for  the  Cognigen  E-Commerce  Division  over  a 3 year
          period.

     e.   Permission to insert  banner  advertising  for  non-telecommunications
          products  on the bottom  margin of Buyer's Web sites for a period of 4
          years at no cost.

3.       ASSETS SELLER WILL DELIVER AT TME OF CLOSING:

3.1  All of its agency,  reseller and other  agreements and contracts Seller has
     with carriers, switched resellers,  unswitched resellers,  consolidators or
     other providers of long distance and local telephone service.

3.2  All accounts receivable,  commissions  receivable,  future commissions that
     are  and may be  payable  from  any of the  carriers,  switched  resellers,
     unswitched resellers, consolidators or other providers of long distance and
     local telephone service.

3.3  All computer software,  proprietary  programs and applications,  computers,
     monitors,  peripherals,  printers,  copiers, telephone PABX systems, office
     furniture and fixtures,  office leases, belonging to and used by the Seller
     in the conduct of its business.

3.4  All  of  the  Seller's  customer  databases,  customers  lists,  print  and
     electronic records relating to customers.

3.5  Inventories and orders for prepaid  telephone  cards.  3.6 All new accounts
     generated via Seller's Web sites or through direct sales. 3.7All Web sites,
     pages,   links  and   agreements   related  to  the  conduct  of  its  core
     telecommunications  business  as well as all  Internet  domains,  and email
     addresses.

3.8  All of the Seller's  agreements with agents and their  subagents  within or
     without its multilevel  marketing system.  3.9 Exclusive use and control of
     the name "Cognigen" and its attendant copyright,  trade name, trademark and
     service mark registrations both federal and state that may exist.

3.10 All other intellectual  property of the Seller owned and used in connection
     with the conduct of its core telecommunications business.

3.11 All its lines of credit with  carriers,  prepaid card  providers,  switched
     resellers,  switchless  resellers  and  other  providers  of local and long
     distance phone service.

4.       SELLER'S REPRESENTATIONS AND WARRANTIES:

4.1  Seller warrants that pursuant to its articles of incorporation  and by-laws
     it has the legal  right to enter into the  present  Agreement.  Seller also
     warrants  that it has the  required  corporate  authority to enter into and
     conclude  this   transaction   as  evidenced  by  the  attached   corporate
     resolution.

4.2  That the  transaction  provided for in this  Agreement is not prohibited or
     affected by indentures,  mortgages,  loans, credit  arrangements,  or other
     agreements.

4.3  Seller warrants it has good title to the above listed assets.

4.4  Seller  warrants  that  affecting  it  there  is  no  litigation   pending,
     outstanding,  or adverse  actions known.  4.5 Seller  warrants it holds all
     permits,  licenses,  approvals  required  by law  for  the  conduct  of its
     business.

5.       BUYER WILL DELIVER AT TIME OF CLOSING:

5.1  The shares of stock provided for in paragraph 2.1(a),

5.2  A promissory note made by the Buyer in favor of the Seller in the amount of
     $300,000 as provided for in paragraph 2.1(b), and

5.3  Delivery of an executed  contract of  employment  provided for in paragraph
     2.1(c).

6.       TERMS OF DEFAULT BY BUYER OR SELLER:

6.1  Failure of any party to the Agreement  insisting upon strict performance of
     the provisions  hereof shall not be construed as waiving their rights under
     it.

6.2  Default  by either  party in their  performance  of the  provisions  of the
     Agreement  constitutes legal basis for the rescission or termination by the
     other party.

6.3  Either party shall have 30 days from date of  notification  of such default
     to cure or remedy the default.

7.       SELLERS DECLARATION RELATIVE TO FINANCIAL STATEMENTS:

7.1  Seller  declares  that to the best of its  information  and  knowledge  the
     financial  statements,  analyses and reports submitted to the Buyer for the
     years reported and any interim periods are unaudited, complete, correct and
     prepared by Seller's  management  in  accordance  with  generally  accepted
     accounting principles consistently applied for the periods covered.

7.2  Seller further declares that such  statements,  analyses and reports fairly
     present  the  financial  condition  of  the  company  and  the  results  of
     operations for the covered periods.

8.       BUYER'S REPRESENTATIONS AND WARRANTIES:

8.1  The  execution,  delivery,  and  performance  of this  Agreement  has  been
     authorized  properly and is a valid and legally  binding  obligation of the
     Buyer.

8.2  There are no actions,  suits or  proceedings  that have been  instituted or
     threatened by a court or government  agency or body that casts doubt on the
     Buyer's ability to conclude this Agreement, or its legality or validity.

9.       OBLIGATIONS OF THE SELLER AND THE BUYER:

9.1  Both Seller and Buyer declare that all applicable laws and regulations that
     may  affect the  execution  and  fulfillment  of this  Agreement  have been
     complied with.

9.2  Seller shall be responsible for the full and orderly  transfer and delivery
     to the Buyer of the  assets  listed in  paragraphs  3.1 to 3.11 and as more
     fully detailed in Annex A, attached hereto and made a part hereof.

9.3  Seller shall be responsible to assure that the conduct of business prior to
     closing will be in the  ordinary  course of events,  consistent  with prior
     practice.  The  business  will be kept  intact with  employees,  suppliers,
     landlords, and customers.  Seller will assist Buyer in obtaining employment
     agreements or other agreements, if needed, with certain or all officers and
     employees.

9.4  Seller will provide best efforts to make  available to Buyer full access to
     its books, records and latest financial statements.

9.5  Seller  will  assist and provide  the  required  signatures  to transfer to
     Buyer's control all required bank accounts,  or to open new accounts and to
     transfer funds as may be appropriate.

9.6  Buyer shall carry out the completion of this Agreement in all respects.

10.      INDEMNIFICATION:

10.1 Seller shall  indemnify  Buyer  against  losses or costs arising out of (1)
     liabilities that were not  contemplated or disclosed,  but that should have
     been, (2) misrepresentations, or (3) breaches of warranties.

10.2 No adjustments or indemnification to purchase price shall, however, be made
     that will affect the  integrity of the number of Buyer's  shares issued and
     transferred to Seller.

11.      CLOSING:

11.1 Closing of this  transaction  shall take place concurrent with execution of
     this Agreement by the Parties.

12.      MISCELLANEOUS:

12.1 This Agreement shall be binding upon the legal  successors and assignees of
     the parties.

12.2 Notices to the parties  shall be  communicated  as follows:  Seller  Laurel
     Anderson,  CCC 300 Queen Anne Avenue  North,  Suite 644  Seattle,  WA 98109
     Buyer: Peter Tilyou,  ITHC 2608 Second Avenue,  Suite 108 Seattle, WA 98121

12.3 This Agreement and attached  exhibits are complete and represent the entire
     agreement  between the parties,  and supersede  other prior  agreements and
     understandings.

12.4 This Agreement is subject to the laws and jurisdiction of the courts of the
     State of Delaware.

13.      EXHIBITS:

13.1 Seller's Corporate Resolution

13.2 Buyer's  Promissory  Note

13.3 Kevin Anderson Employment Contract

13.4 Buyer's Corporate Resolution

13.5 Annex A, List of Assets

         IN WITNESS  WHEREOF,  the  Parties  have caused  this  Agreement  to be
executed as of the day and year set forth above.

Inter-American Telecommunications Holding Corporation


By:/s/Peter Tilyou
   --------------------------------
   Peter Tilyou, Authorized Officer



Cognigen Corporation


By:/s/Laurel Anderson
   -----------------------------------
   Laurel Anderson, Authorized Officer


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PROMISSORY NOTE

         July 1, 1999                                    $300,000


         On or  before  ninety  days from the date  hereof,  without  grace,  we
         promise  to pay to the  order  of  Cognigen  Corporation  (NV),  at its
         offices  in  Seattle,  Washington,  the sum of THREE  HUNDRED  THOUSAND
         DOLLARS  ($300,000)  together with interest at the rate of 8% per annum
         until paid. We waive demand and presentment. In case suit is instituted
         to effect  collection we agree to pay reasonable  attorneys fees, which
         shall not in any circumstance exceed 15% of the face value hereof.

         Inter-American Telecommunications Holding Corporation (DE)


         By:
            --------------------------------
            Peter Tilyou, Authorized Officer






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