Bristol Myers poised to give up modest gains tied to AstraZeneca deal talks

Shares of Bristol Myers Squibb BMY.N were on track to erase the slim gains made since talks of a mega-deal with AstraZeneca AZN.L emerged on Sunday.

The stock fell 0.25% in premarket trading.

Several analysts had expressed doubt about the benefits of such a transaction. "We are a bit perplexed by the news. If there is one company that doesn't need financial engineering, it's AstraZeneca," brokerage firm Jefferies wrote.

A punishing selloff in AZN shares on Monday knocked it off its spot as the second-biggest company in the UK by market cap. With a market value of 190.11 billion pounds ($255.63 billion), energy giant Shell SHEL.L is now the second largest company in the UK.

Before the potential deal was reported, BMY had jumped 21% year to date, while AZN fell 8.4%.