Tullow Oil said its recent Ghana discovery may contain recoverable reserves in excess of 1.3 billion barrels, as the company reported lower first-half profits on Tuesday.

Tullow said in a statement that net income fell in the first half of the year to 36.6 million pounds from 95.4 million pounds in the same period of 2006, as a mild winter hit demand for, and prices of, North Sea gas.

A company-compiled poll of 10 analysts gave an average forecast of 51 million for fist half net income.