Spain's Santander (SAN.MC) said it was not considering buying out the 28 percent of its U.S. auto finance business that is currently listed on the stock market after Bloomberg reported earlier on Tuesday the Spanish bank was mulling such a move.

"Regarding a news report published today that Banco Santander is considering a possible offer to acquire the publicly traded shares of Santander Consumer USA Holdings, Banco Santander announced that it is not considering this option," the bank said in a short emailed statement.

The stake in Dallas-based Santander Consumer USA Holdings Inc, which is 60-percent owned by Santander, was worth about $1.8 billion as of Monday.

Shares in Santander Consumer (SC.N) closed up 1.7 percent on Tuesday at $18.61 a share after they rose more than 13 percent during the day. The unit was listed on the New York Stock Exchange in January in an offering priced at $24 per share.