UPDATE 1-Tullow Oil's sale of stake in Uganda project to Total, CNOOC dropped

* Total, CNOOC did not further extend deadline for sale - Tullow

* Uganda authorities did not agree tax relief on deal

* Tullow seeking to reduce Uganda stake from third to around 11% (Adds detail, analyst comment)

By Shadia Nasralla

LONDON, Aug 29 (Reuters) - Tullow Oil's plan to sell another stake in its 230,000 barrel per day project in Uganda to France's Total and China's CNOOC has been called off due to a tax dispute with the Ugandan authorities, Tullow said on Thursday.

The London-listed firm had previously sold about two-thirds of the project to CNOOC and Total for $2.9 billion, in transactions completed by 2012.

It had planned to sell the two companies around another roughly 22% holding in the project in a deal that had been expected to close in late 2018.

That would have cut Tullow's remaining stake to about 11%, raising $200 million that would have helped the firm cut its net debt, which stood at $2.9 billion at mid-year, and reduce its operational commitments to the project by around $700 million.

Tullow said the firms could not reach an agreement with the Ugandan Revenue Authority on the tax relief on money Total and CNOOC would have paid to Tullow, leading to the majors declining to extend the deadline for the deal to be completed.

Shares in Tullow were down around 3.3% at 210.1 pence at 1157 GMT.

"Tullow will now initiate a new sales process to reduce its 33.33% operated stake in the Lake Albert project, which has over 1.5 billion barrels of discovered recoverable resources," it said.

The firm said the partners in the Uganda project had aimed to reach a final investment decision on development by the end of 2019 but that terminating the stake sale "is likely to lead to further delay".

Chief Executive Paul McDade told Reuters it was too early to give a new timeframe for the final investment decision or to talk about potential new partners in the project. He said Total and CNOOC had not yet indicated their view on a fourth partner coming in.

"Whilst frustrations around the project were clear, the termination of the (sale and purchase agreement) and inevitable further delay to the project was an unlikely scenario," said David Round, analyst at BMO Capital Markets.

"Whilst removal of the deal, resultant delay, and project risking clearly impacts valuation, this also has repercussions for Tullow's growth and deleveraging story, and puts more pressure on the on-going programme in Guyana."

Tullow has just made a discovery and is doing further exploration work offshore Guyana, one of the world's most-watched basins. (Reporting by Shadia Nasralla; Editing by Edmund Blair and Jan Harvey)