LONDON, Feb 26 (Reuters) - Commodities pricing agency Platts said on Monday its addition of U.S. WTI Midland crude into the global Brent oil benchmark has gone well, and it won't be necessary to add any further crudes for the time being.

Platts, part of S&P Global Commodity Insights, added Midland to its dated Brent price assessment in May 2023, bolstering volumes underpinning the benchmark amid diminishing output of the five North Sea grades, Brent, Forties, Oseberg, Ekofisk and Troll.

The integration of Midland has gone "smoothly," Vera Blei, head of Established Benchmarks at S&P Global Commodity Insights, told the company's London Energy Forum on Monday.

"Midland coming into dated Brent has added a significant amount of volume with a grade that was already established in Europe," she said.

The volumes Midland brings to the benchmark should future proof it for the next decade or so, Blei said, but the company did not rule out future additions.

Platts has learned by adding Midland that it is possible to expand the benchmark using crude from outside the North Sea, she said when asked if any more additions were being planned.

"This is a long undertaking," she said. "We can introduce a grade from outside of the North Sea successfully if we have to."

The Midland addition serves "to really futureproof this for the next decade," she added. "It doesn't mean we won't be looking at new grades as and when that becomes necessary."

The addition of Midland has helped bring new counterparties to the North Sea benchmark trading environment, Blei said, including U.S. oil company Occidental and Saudi Aramco . (Reporting by Robert Harvey and Alex Lawler, editing by Susan Fenton)