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* Rolls-Royce jumps as 2023 profit more than doubles

* Beazley gains on $300 mln shareholder return

* FTSE 100 flat, FTSE 250 adds 0.2%

Feb 22 (Reuters) - The UK's FTSE 100 was relatively unchanged following an initial rise on Thursday, as a slide in shares of AstraZeneca offset the gains from Rolls-Royce and Beazley on upbeat corporate updates.

The blue-chip FTSE 100 held its ground at 7,661.22 points, as of 0934 GMT.

Investors digested a series of corporate updates, with Beazley climbing 9.2% to lead the blue-chip index after the insurer allocated around $300 million for shareholder returns.

Rolls-Royce advanced 6.4% as the engineering company reported a more than two-fold jump in profit in 2023 and forecast further growth this year. Meanwhile, Anglo American added 3.5% as the miner said it would review its assets, after posting a 94% slump in annual profit.

The gains on the FTSE 100 were, however, limited as shares of heavyweight AstraZeneca fell 1.6%, with the drugmaker's stock trading ex-dividend.

Global upbeat sentiment following chip designer Nvidia's stellar results failed to enthuse UK stocks, underperforming the pan-European benchmark STOXX 600 index , which notched a record high.

"It is a mixed bag with regards to the FTSE 100 and is still greatly underperforming its peers...it doesn't have any technology stocks," said Axel Rudolph, senior market analyst at IG Group.

"Germany, for example, has SAP. In the UK, we've got none and that's why we have this underperformance, because there is no benefit from this AI (Artificial Intelligence) frenzy."

The mid-cap FTSE 250 index added 0.2%, led by an 18% jump in

Indivior Plc

as the drugmaker's annual profit soared 27%. Additionally, the firm said it is considering shifting its primary listing to the U.S. by the middle of this year, the latest to join the list of companies leaving London.

Separately, Britain's economy maintained its early 2024 momentum, with a survey showing strong growth for services firms and business optimism at a two-year high. (Reporting by Shristi Achar A in Bengaluru; Editing by Savio D'Souza and Dhanya Ann Thoppil)