The new head of Qatar's sovereign wealth fund, Ahmad al-Sayed, is known and feared as a hard, aggressive negotiator - and his appointment signals the fund's ambitious overseas acquisition plans are likely to continue. Qatar's newly-crowned emir removed former Prime Minister Sheikh Hamad bin Jassim al-Thani as chief executive at Qatar Investment Authority (QIA) on Tuesday, replacing him with Sayed, a lawyer previously in charge of running the fund's investment arm. The fund, with estimated assets of $100-$200 billion, has been actively deploying the nation's riches from natural gas in recent years in a string of high-profile assets ranging from German sports-car maker Porsche to British bank Barclays and Swiss lender Credit Suisse. A broader transition in the Gulf state saw the emir hand over power to his 33-year-old son Sheikh Tamim bin Hamad al-Thani last month. It led to speculation among bankers and the investment community that the sovereign fund - widely seen as one of the world's most aggressive investors - may take a more cautious stance. However, the appointment of Sayed indicates otherwise. In his previous job as chief executive of Qatar Holding, he anchored some of the fund's largest overseas investments. He showed his steel when he went up against Glencore last year, when the fund threatened to vote down the commodities giant's acquisition of London miner Xstrata. YOUNGER GENERATION Qatar eventually voted in favor of the merger after Glencore chief agreed to raise terms for the deal. "I think it's a good sign in terms of continuity. Having Ahmad, as well as retaining Hussain al-Abdulla on the board, signals that it's business as usual," said one Doha-based banker who works closely with the fund. "Ahmad doesn't come from a remarkably prominent family. He's there on merit." Sayed, in his late 30s, has strong influence among members of Qatar's royal family who must sign off on all big decisions. His elevation to the fund's top role is an indication that the new emir is keen to hand over more responsibilities to a young generation. It is also a positive sign those banks and advisory firms seen as closer to the fund, who will receive more business if the fund continues its aggressive investments. Credit Suisse - in which the fund holds the second-largest ownership stake, of 6.2 per cent - is widely seen as a preferred choice for the fund having won several large advisory mandates in the past. The fund has also increasingly used boutique advisory firms such as Lazard, Evercore Partners and Perella Weinberg in recent years on big deals.