By Purvi Agarwal and Pranav Kashyap

(Reuters) -London's benchmark equities index was flat on Monday after a four-week bull run, in caution as top U.S. and Chinese officials met in London to try and defuse a high-stakes trade dispute.

The FTSE 100 closed flat at 8,832.28 points, while the mid-cap FTSE 250 was up 0.6%.

A meeting with top officials from the U.S. and China unfolded in London that investors hope will produce some progress in de-escalating trade tensions between the world's two biggest economies.

The discussions emerged from a phone call between the nations' respective presidents last week, where they pledged to continue dialogue amid a trade war that threatens a global supply chain shock and slower economic growth.

British finance minister Rachel Reeves will hold a meeting with Chinese vice premier He Lifeng, although there were no details on when the talks would be held.

London stocks rounded off the previous week with gains and logged a fourth straight week of advances, the longest in nearly five months.

A U.S. jobs report on Friday allayed concerns of an economic slowdown in the world's biggest economy despite a U.S. tariff roller coaster.

The non-life insurers index led losses among sectors, ending down 1.3%.

Pharma stocks dipped 0.4%, as investors looked to book some profits.

Among individual stocks, WPP slipped 2.8% to the bottom of the FTSE 100 after the ad group said its Chief Executive Officer Mark Read would retire by the end of 2025.

Spectris soared 60%, leading FTSE 250 gains, after the scientific instruments maker said it has received a takeover proposal from private equity firm Advent valuing its shares at 37.35 pounds per share.

Alphawave jumped 18.9% after U.S. chipmaker Qualcomm agreed to acquire the semiconductor company for about $2.4 billion.

Asset manager M&G rose 3% after UBS upgraded its rating to 'buy' from 'neutral'.

(Reporting by Purvi Agarwal, Pranav Kashyap and Ragini Mathur in Bengaluru; Editing by Maju Samuel and Chris Reese)