Baseball put a moratorium in place before a group of executives toured the country last month, said MLB President Bob DuPuy. It lifted the ban briefly to allow the New York Yankees and Seattle Mariners to sign two players each last week because the clubs had previously notified MLB about the negotiations.

"The entire system of how we will work with the Chinese to ensure that their baseball program is able to develop, yet at the same time allow major-league clubs access to the players, is what is under review," DuPuy said in an interview.

Major League Baseball is trying to make the game more popular in China, where the sport was outlawed in 1959. It returned in 1975 and the Chinese Baseball League was formed in 2002.

Baseball will keep the ban in place until the end of the season, when it will likely devise a plan, DuPuy said. China is the only country off limits to teams in search of talent. Baseball has agreements with other nations including Japan, where clubs must follow special rules to acquire players.

The Yankees, who have asked baseball to play games in China, became the first team to sign Chinese players and reach a sponsorship agreement with a Chinese company. The Yankees signed two 19-year-olds on June 18 and reached a deal this week with Yili Group Holding Co., China's biggest dairy products company.

The Mariners signed their players, a 24- and a 28-year-old, on June 20.

Baseball is trying to stage exhibition games in China next March, though after reviewing the condition of the stadium being built for the 2008 Olympics in Beijing, DuPuy said he has concerns.