UPDATE 1-Blackstone weighs bid for TietoEnator -sources

(Adds TietoEnator comment, Cidron bid extension)

LONDON, April 23 (Reuters) - Private equity and real estate firm Blackstone Group LP (BX.N: Quote, Profile, Research) is mulling a bid for Nordic IT services company TietoEnator (TIE1V.HE: Quote, Profile, Research), people familiar with the matter said on Wednesday.

Blackstone has not yet approached the company, the sources said.

TietoEnator has rejected a 15 euro-a-share, 1.08 billion euro ($1.72 billion) total offer from Swedish private equity firm Nordic Capital's Cidron unit for being too low.

"Blackstone is contemplating a counter offer," one of the sources familiar with the matter said.

Norwegian computer services company EDB Business Partner (EDBASA.OL: Quote, Profile, Research) said on Tuesday it was keeping a close eye on TietoEnator (TIE1V.HE: Quote, Profile, Research), but has not made an offer.

TietoEnator Chairman Matti Lehti said he would not comment what he referred to as market rumours.

"The air is thick with different views now, but we cannot comment on these," he told Reuters.

Blackstone declined to comment.

Nordic Capital said on Wednesday it would extend its offer period to May 9 from April 28 due to a continuing EU merger regulation procedure. (Reporting by Eleanor Wason; Additional reporting by Sami Torma; Editing by Quentin Bryar)