Dec 15 (Reuters) - The following are the top stories in the Financial Times. Reuters has not verified these stories and does not vouch for their accuracy.
* Spain's Grifols buys NAT unit of Hologic for $1.85 bln on.ft.com/2h2hTvi
* NYSE to buy National Stock Exchange as it eyes new pricing model on.ft.com/2h2eTPR
* Yahoo reveals 1bn users were hit by hacking attack on.ft.com/2h2bQHh
* ExxonMobil names former refining head as new chief on.ft.com/2h2aa0q
* Uber ordered to halt its self-driving test in San Francisco on.ft.com/2h2blNd
- Spanish Healthcare group Grifols is buying the nucleic acid testing unit of Hologic for $1.85 billion. Deal includes a plant in San Diego along with development rights and licenses to patents and access to product manufacturers.
- New York Stock Exchange agreed to buy the National Stock Exchange. It also agreed to keep the National Stock exchange open. The deal will give the exchanges operator a fourth U.S. exchange licence and one that would be distinct from NYSE, NYSE MKT and Arca.
- Struggling internet giant Yahoo said hackers stole personal data on more than a billion users in 2013. This announcement comes after the summer's disclosure of another intrusion in 2014 that affected 500 million Yahoo accounts.
- Darren Woods, former head of its refining and transport operations, was appointed as Exxon Mobil's new chief executive, following the retirement of Rex Tillerson who has been picked by Donald Trump to be his secretary of state.
- Uber has been ordered by California highways regulator to pull its self-driving cars off the roads of San Francisco while it obtains the required permit, less than a day after it began the pilot in its hometown. (Compiled by Sangameswaran S in Bengaluru; Editing by Sandra Maler)