They had agreed a fee with Rangers for Buffel in January but missed out on signing the Belgium international after being unable to resolve differences in contract negotiations.
Hannover considered themselves in need of a playmaker, but the Bundesliga have dropped those plans after Dutchman Arnold Bruggink belatedly found form in his first season with the club.
Bruggink experienced a difficult first half-season with Hannover but became an influential player over the closing months of the campaign, winning four man-of-the-match awards.
It is believed that Rangers will let Buffel leave Ibrox, if they receive an acceptable offer for the player who cost £2.3million from Feyenoord at the start of 2005.
Hecking told Rangers official website: "We were keen to bring him to Hannover during the winter break but unfortunately it never worked out for both parties.
"We won't be going back in for him, though, as our priorities for this summer have changed.
"We have a Dutchman playing in a similar position, Arnold Bruggink, who finished the season very strongly for us and so we don't feel we need to sign another player of this type right now."
Buffel recently vowed to salvage his ailing Ibrox career under manager Walter Smith next season.
The 26-year-old has been in and out of the Light Blues side ever since joining, and is now on the way back to full fitness after he required surgery on a knee injury.
Declaring he has "unfinished business" at Rangers, Buffel insisted he would rather stay at Rangers than move on.