CINCINNATI – Pete Rose autographed and wrote apologies for betting on baseball on balls for friends but never expected the balls to be sold publicly, his business agent said Monday.

A New Jersey auction house plans to put 30 such balls up for bid in April, unsure how much they’ll fetch. The baseballs belonged to a memorabilia collector who died in December.

Baseball’s banished hits king signed the balls for some of his friends about a year ago but didn’t want them put up for sale, according to business agent Warren Greene.

“These guys are collectors. Pete signed for them,” Greene said. “Pete made zero dollars for signing them.”

The baseballs say “I’m sorry I bet on baseball” in block letters, with Rose’s autograph directly below. Greene didn’t know who suggested the inscription.

Rose accepted a lifetime ban for gambling in 1989, but denied betting on baseball for nearly 15 years. He finally acknowledged in his latest autobiography, published in January 2004, that he had bet on baseball while he managed the Cincinnati Reds.

During his exile from baseball, Rose has made a living in part off his memorabilia signings. During an appearance years ago, he agreed to sign a fan’s copy of baseball’s Dowd Report, which contained the evidence that he bet on baseball.

Greene said a collector who got some of the “I’m sorry” baseballs gave 30 of them to Barry Halper, a limited partner in the New York Yankees. After Halper’s death, his family contacted Robert Edward Auctions to sell his sports memorabilia.

“There was a box of these baseballs,” auction house president Robert Lifson said. “When I saw them, I couldn’t help but thinking, ‘Wow.'”

Lifson couldn’t guess how much fans will bid for the apology baseballs. Rose’s Web site features autographed balls for $86.99. Other balls with inscriptions such as “Hit King” are offered for $104.