Global newsbriefs from the Economist

Pfizer called off its $160 billion merger with Allergan after the U.S. Treasury proposed new rules that would severely curtail the benefits of "inversion" takeovers (where a U.S. company buys a foreign one in order to reduce its corporate-tax bill). Allergan is listed in New York but has its corporate headquarters in lower-taxed Ireland, which is where Pfizer would have based the newly combined company. Such deals have become politically toxic in the U.S.

The U.S. Department of Justice filed a lawsuit to stop the $25 billion merger of Halliburton and Baker Hughes, the world's second- and third-largest oilfield-services companies, citing antitrust concerns. The merger was announced in November 2014 but opposed by some big oil companies. They worried that diminished competition in oil services would put a further squeeze on profits already hit by the fall in oil prices.

The share prices of big French telecom companies plunged after the collapse of a proposed $11.4 billion merger between Orange (formerly France Télécom) and Bouygues. The negotiations failed to resolve differences over the value of the deal and the French government's 23 percent stake in Orange.

The Reserve Bank of India cut its benchmark interest rate from 6.75 percent to 6.5 percent, the lowest it has been in five years. Inflation, usually a headache for the central bank, has eased.

A new "fiduciary rule" on financial advice was published by the U.S. government. From now on, almost anyone giving investment advice will be required to act in the "best interest" of their clients. They previously had to ensure they were giving only "suitable" advice.

Anbang, a Chinese insurance company that has been buying hotel assets overseas, dropped its bid for Starwood Hotels, which counts the Sheraton and Westin chains among its brands. Marriott had already struck a deal to take over Starwood before Anbang launched its rival offer.

A flutter of consolidation among America's smaller airlines looked likely after Alaska Airlines agreed to buy Virgin America in a $4 billion deal. The new carrier will become America's fifth largest. Virgin America was started by Richard Branson in 2004.

India's government welcomed the news that 1 billion people are now enrolled in its biometric-identity scheme, known as Aadhaar. After people register their fingerprints and retinal patterns, they are issued a card that gives access to public benefits. The government claims this is producing savings, but a proposal in Parliament to allow security agencies to tap the data has raised privacy concerns.

An international consortium of journalists published an investigation of a huge leak of documents from Mossack Fonseca, a Panamanian law company specializing in offshore shell companies. The documents shone a light on the sometimes embarrassing finances of top government officials around the world. Those caught up included Petro Poroshenko, the president of Ukraine; close associates of Vladimir Putin, Russia's leader; and Sigmundur David Gunnlaugsson, Iceland's prime minister, who stepped down after large protests.

Frontex, the European Union's border agency, began returning migrants from Greece to Turkey under a deal struck last month to control the flow of Middle Eastern asylum-seekers. Only 202 migrants were sent back; further deportations were postponed because of delays in processing asylum applications. But the number of migrants entering Greece has already begun to fall.

Fighting broke out in Nagorno-Karabakh, a mostly Armenian enclave in Azerbaijan that has been occupied by Armenia since the collapse of the Soviet Union. Azerbaijan said 16 of its soldiers had been killed, while the Armenian side claimed to have lost 20.

A court in Northern Ireland, where abortion remains illegal in most cases, handed down a three-month suspended sentence on a woman who used medication bought online to terminate her pregnancy. She could not afford to travel to England, where abortion is legal.