NEW YORK (CNN/Money) - PepsiCo Inc. entered an agreement Monday to replace Coca-Cola as the beverage of choice on board United Airlines flights.

The agreement is slated to begin May 1 when Pepsi and Diet Pepsi will replace Coke (KO: up $0.43 to $51.68, Research, Estimates) and Diet Coke on United's (UAL: down $0.35 to $15.35, Research, Estimates) domestic and international flights.

Financial terms of the pact were not revealed, but it is expected to cover $25 million in cola sales over the five years, according to a report in the Wall Street Journal. The agreement is "a more expensive program this time around...The financial package alone was very attractive," a United spokesman told the paper.

In addition, Purchase, N.Y.-based PepsiCo is in talks to put its Aquafina bottled water product in Diageo PLC's Burger King restaurants, the Journal reported, citing people familiar with the negotiations.

Shares of Pepsi (PEP: up $0.66 to $51.56, Research, Estimates) gained ground in midday trading Monday.