* Brent system moves around 100,000 bpd from 20 oilfields
* TAQA takes over from Shell UK E&P Aug. 1
(Writes through with deal signing, background)
LONDON, Aug 3 (Reuters) - The UK arm of the Abu Dhabi National Energy Co TAQA.AD, TAQA Bratani Ltd, has taken over as operator of the North Sea Brent system pipeline and facilities from Aug. 1, it said on Monday.
TAQA said it replaced Shell UK Exploration and Production, a unit of Royal Dutch Shell (RDSa.L), which had held the position since the mid 1970s.
A spokeswoman for Shell had no immediate comment.
Last year, Shell issued a statement when the deal was signed, saying that, together with Esso Exploration and Production UK Limited (XOM.N), it had agreed to sell equity interests to TAQA.
Brent was once Britain's largest oilfield and has global significance as part of the European benchmark, used for pricing around two thirds of internationally traded crude oil.
As the North Sea province has matured, production of the Brent stream, from a series of linked fields, has dwindled to just over 100,000 barrels per day (bpd).
To make the benchmark more liquid, three other North Sea crude oil grades -- Forties, Oseberg and Ekofisk -- have been bolted on to the marker grade.
Increasingly, the mature North Sea is dominated by smaller players as major companies have pursued economies of scale in bigger, more accessible oilfields elsewhere.
A TAQA company statement on Monday quoted TAQA Managing Director Leo Koot as saying the new role was an excellent fit with TAQA's growing North Sea portfolio and underlined the company's commitment to being a leading player among the energy producers for the British North Sea.
"This is the latest step in our North Sea activity programme which this year already has seen TAQA increase production from our operated assets, initiate drilling and near-field exploration," Koot said.
The Brent system is jointly owned by 21 companies.
It consists of part of the processing systems and structure on the Cormorant Alpha platform, operated by TAQA, as well as a 150 km pipeline connecting Cormorant Alpha to the BP (BP.L) operated Sullom Voe Oil Terminal in the Shetland Islands. TAQA owns a 24 percent share of that terminal.
The Brent System is responsible for transporting oil from around 20 North Sea oilfields, accounting for about 37 percent of the Sullom Voe Terminal input and around 8 percent of British offshore oil production, TAQA's statement said. (Reporting by Christopher Johnson and Barbara Lewis; editing by Sue Thomas)