The Dow Jones Industrial Average was down while the S&P 500 Index and the Nasdaq Composite were up slightly to kick off the trading week following the Presidents' Day holiday on Monday.

In company news, Medtronic (MDT) reported fiscal Q3 non-GAAP earnings Tuesday of $1.39 per diluted share, up from $1.30 a year earlier and above the consensus estimate of analysts surveyed by FactSet calling for $1.36. Fiscal Q3 revenue was $8.29 billion, up from $8.09 billion in the year-ago period but below the FactSet consensus estimate of $8.33 billion. Medtronic shares were down 7.4% near noon.

Walgreens Boots Alliance's (WBA) go-private talks with Sycamore Partners are "now alive," CNBC's David Faber said Tuesday, according to media reports. In January, Faber said the talks were "mostly dead." Walgreens shares were up 12%.

Southwest Airlines (LUV) plans to cut 1,750 corporate jobs, including senior leadership roles and directors, the company said late Monday. The planned layoffs represent about 15% of its workforce, Southwest said. Shares of the airline were down 0.3%.

United Rentals (URI) said Tuesday it does not intend to submit a revised bid to acquire H&E Equipment Services (HEES), allowing H&E to terminate their previously announced merger agreement. Under the agreement, H&E must pay a fee of about $63.5 million to terminate the deal, United Rentals said. Following the termination, United Rentals said it will immediately restart its share repurchase program. As of Tuesday, about $250 million of authorization remains of the company's existing $1.5 billion buyback program. Shares of United Rentals were down 3.9%, while those of H&E were up nearly 15%.

Diamondback Energy (FANG) on Tuesday agreed to acquire certain subsidiaries of Double Eagle IV Midco for about 6.9 million Diamondback shares and $3 billion in cash, the company said. The deal is expected to be complete on April 1, subject to regulatory approval. Diamondback shares were up 0.6%.

Honda Motor (HMC) is open to resuming takeover talks with Nissan if Nissan Chief Executive Makoto Uchida steps down, the Financial Times reported Monday, citing sources familiar with the discussions. Honda shares were down 3.7%.

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