New York ? When two teams compete in the same market, there is usually grudging acknowledgment between them. Nowhere do the feelings run deeper than in New York, where the Giants once returned mail from the Jets unopened and Ranger fans still jeer ex-Islander Denis Potvin, 14 years after he retired.

Now, though, an era of good feeling has emerged between the baseball Mets and Yankees, generated by free-agent signings.

The Yankees’ brain trust is headed by Joe Torre, who first managed the Mets, pitching coach Mel Stottlemyre, who had the same job at Shea Stadium, and dugout coach Don Zimmer, forever a footnote in Mets history because he went 0-for-34 in their first season.

Robin Ventura was traded by the Mets to the Yankees last year, the first deal between the teams in eight years, and then re-signed with the Yankees during the offseason.

Then the Yankees signed Todd Zeile, who was Ventura’s best friend with the Mets. Not to be outdone, the Mets scooped up ex-Yankees reliever Mike Stanton, who joined ex-Yankee Al Leiter on the pitching staff.

The Ventura trade was a landmark deal because it marked just the sixth time the teams had exchanged players. No major league players had passed between the teams since 1992.

“There’s a reason it takes eight years to make a deal,” Yankees GM Brian Cashman said then. “We’re in competition with each other. You always tread carefully with each other and respect each other from afar. It could be another eight years, who knows?”

There have been no other trades, although the Stanton signing was somewhat related to the Ventura deal. The Mets acquired David Justice for Ventura and then almost immediately traded him to Oakland for reliever Mark Guthrie. After one year, Guthrie was not offered arbitration and his spot in the bullpen went to Stanton.

Mets GM Steve Phillips noted the cross-pollination of players between the teams.

“It’s hard to think that the rivalry could be fueled any more than it already is,” he said. “But it may be. We’ll see what happens.”

Relations between the Mets and Yankees have always been frosty, ever since spring training 1962, when Mets manager Casey Stengel used his best two pitchers, Roger Craig and Al Jackson, to win the first exhibition game between the teams.

The expansion team’s triumph over their haughty neighbors was a benchmark, especially in Toots Shor’s Manhattan saloon, where the proprietor reported the patrons were celebrating like it was New Year’s Eve.

Ever since George Steinbrenner took over stewardship of the Yankees in 1973, spring-training games between the teams have been treated like Armageddon.

Lately, though, each team has been attracted by the other’s players.

Since 1996, not counting Justice, nine players have shown up on both New York teams — Ventura, Zeile, Stanton, Kenny Rogers, Tony Tarasco, Allen Watson, Lance Johnson, Darren Bragg and Jose Vizcaino.

Vizcaino was a Yankee only briefly, just long enough to break his old team’s heart by delivering the game-winning hit in the opening game of the 2000 World Series.

That was the same year that Roger Clemens beaned Mike Piazza in the regular season and then threw a broken bat in his direction in Game 2 of the World Series, prompting a $50,000 fine and inflaming Mets fans.

The Mets responded by refusing to allow the Yankees to use their Shea Stadium training room during interleague games. Stanton was one of the players barred. That won’t be a problem for him next season.