Flood and Tait were brought through by axed coach John Fletcher
England stars Toby Flood and Mathew Tait will leave Newcastle at the end of this season.
Tait will move to Sale Sharks, while Flood's destination is as yet unknown.
Both players had a year left on their contracts at Newcastle and Falcons chairman Dave Thompson said they would receive transfer fees for the pair.
Sale boss Philippe Saint Andre said Tait's signing was "fantastic" news for the Sharks, describing the 22-year-old as "a naturally gifted rugby player".
Tait, who only signed a new one-year deal with the Falcons at the end of February, can play at full-back, wing or outside centre.
Saint Andre said: "He has already won 23 caps for England and has still tremendous potential to develop further as a player".
The 22-year-old Tait said he had "really enjoyed" his time at Newcastle but was "now looking forward to a new challenge at Sale Sharks and playing with a different group of players".
In addition to Tait and Flood, Newcastle will also lose flanker Ben Woods at the end of the season.
The trio's exit rounds off a dismal season for the Falcons, who are currently 10th in the Guinness Premiership ahead of Sunday's home game against play-off challengers Leicester.
Flood is not available to face the Tigers because of an ankle injury that is likely to require surgery and possibly sideline him for England's New Zealand tour next month.
Flood, who has won 17 caps, publicly criticised the circumstances surrounding John Fletcher's departure as Newcastle rugby director in March.
After Fletcher left Kingston Park, Steve Bates was put in interim charge, but the Falcons have still failed to fire despite fly-half Jonny Wilkinson enjoying a relatively injury-free run.
Thompson said: "Having four of our first-choice back line away with England for so long this year, and the fact that they would miss half of our league games next season, has been a major consideration in the decision to allow both Toby and Mathew to move.
We are currently in advanced negotiations with two Super 14 players
Newcastle chairman Dave Thompson
"The impact of four of our back line going out en-masse and then returning at various stages of the season has caused us certain difficulties as we look to get this team to where it needs to be.
"We felt that the situation had to be addressed for the long-term good of the club.
"While we remain committed supporters of England and of English rugby, the interests of Newcastle Falcons remain our foremost concern, and it is with that in mind that we have agreed to these changes."
"We are currently in advanced negotiations with two Super 14 players, and hope to have some positive news to report on that front in the near future."