Approval the financial statements of fiscal year 2010

That earnings distribution shall conform to the principles established in the Statement of the Nation as ISA’s Controlling Shareholder, the corporation’s articles of incorporation, and

ISA announces fourth quarter 2010 results

Approval of the agenda for the shareholder’s meeting

Standard & Poor’s S&P assigned investment grade rating BBB- to ISA, based on the improved risk profile derived from an increase on the Company’s geographic

The power transmission line is approximately 304 km long.

Propositions approved in the Regular Shareholder’s Meeting, held on March 31st, 2011

Starting this coming April 18, 2011, ISA shareholders will receive the first dividend payment of COP 43 per share declared by the Shareholders’ Meeting held

ISA transmitted the 2010 Código País Survey

ISA announces first quarter results 2011

Road concessions and telecommunications encompassing its portfolio in such country

Remittance of end-period financial information in compliance with External Circular 020 of 2011

Resolution 180808 of May 20, 2011 rejects extension by force majeure to the date of commissioning of project 220-kv el Bosque substation

Fitch Ratings Colombia affirmed AAA(col) ratings for ISA 2001 Third Issue of Domestic Public Debt Bonds worth COP 130 billion and the Issue and Placement

Stock Brokerage company Ultrabursatiles reported a pre-arranged operation