Ankara officials will channel money into Turkeys financial markets and banks
Turkeys beleagured currency has bounced back from record lows after Qatar pledged to shore up the banking sectors shaky finances with loans worth $15bn (11.8bn).
A week after a diplomatic spat with the US sent the lira into a tailspin, the agreement with Qatar was calculated to help Turkey avoid having to ask the International Monetary Fund for emergency funding.
Officials in Ankara said the Qatari money would be channeled into Turkeys financial markets and banks, with the implication that the investment would be enough to head off a banking collapse.
However, while the investment gave the Turkish lira much-needed respite, the US president Donald Trumps announcement of further trade sanctions against Ankara, along with concerns about the rising value of the dollar and weak profits in Chinese tech firms, sent global financial markets into reverse.
Londons FTSE 100 sank to its lowest closing level since 26 April after the blue-chip index shed 113 points to 7497, a loss of 1.5%. Germanys DAX closed 1.6% lower, while the Paris-based CAC lost 1.8%.
Many developing markets also suffered losses, which dragged emerging market shares into a bear market, usually defined as a decline by a fifth over a few months.
The MSCIs main emerging markets equities index fell 2%, down 20% on its recent peak in January.
Some analysts said the rout was likely to continue as the US president pressed ahead with higher trade tariffs on Turkey, China and the European Union.
Trump has used his executive powers to impose higher tariffs on steel, aluminium and cars, leading to retaliatory duties on US exports.
The Turkish president,Recep Tayyip Erdoan, retaliated to the latest US tariffs on Wednesday with higher import duties on US imports, including alcohol, cars and tobacco.
Mohamed A El-Erian, the chief economic adviser at the German insurer Allianz, tweeted that Erdoans policies, including the Qatari investment, would act like sticking plaster, leaving the possibility open for an IMF rescue.
He said: This is part of the Turkish governments strategy to avoid the IMF by finding alternative external support. To be a sustainable stabilizer, funding needs to be larger and reach the central bank.
However, the lira rallied by 6% after the Qatari pledge and a separate move by Turkeys central bank to boost the finances of the countrys banks.
In an effort to defend the lira, Turkeys central bank tightened its rules on currency swaps and other foreign exchange transactions, limiting the ability of banks to supply lira to foreign financial companies.
Turkeys trade minister, Ruhsar Pekcan, said: The United States is an important trading partner but it is not our only partner. We have other partners and alternative markets.
Peter OFlanagan, the head of trading at the foreign exchange consultancy Clear Treasury, said: Restrictions from the Turkish central bank limiting banks use of swap lines has had the desired effect on the lira.
Turkey sought to face down the US and currency traders as Erdoan reportedly received support from the German chancellor, Angela Merkel. In a phone conversation the leaders agreed to strengthen bilateral ties and Merkel told Erdoan the strength of Turkeys economy was important to Germany, a presidential source told Reuters.
In another episode of diplomatic activity, Erdoan met the Emir of Qatar, Sheikh Tamim bin Hamad al-Thani, who was on a working visit to see the Turkish president.
Erdoan has accused the US of waging economic war against his country and has vowed not to back down. Ankara more than doubled the tariff on US rice to 50%, increased the US coal tariff to 14% from 10% and more than tripled the tariff on cars to 120%.
Erdoan and Trump are locked in a dispute about the US pastor Andrew Brunson, who was arrested almost two years ago and accused of plotting against the Turkish government. On Wednesday a Turkish court rejected an appeal for Brunson to be released from house arrest and for his travel ban to be lifted but an upper court is yet to rule on the appeal.