LSEG's Lipper reviews transaction affecting fixed-income fund flow data

July 25 (Reuters) - London Stock Exchange Group's (LSEG) Lipper unit said on Saturday it was investigating an unusually large transaction in one investment-grade bond fund that distorted its wider fixed-income fund flow data.

"We are investigating this matter and have identified a sizeable flow within the Short-Intermediate Investment Grade Debt classification that has negatively impacted the fixed income universe," a Lipper spokesperson said, adding that further details would be provided once the data had been validated.

Lipper, which provides fund performance research and data, has removed the fund from its current weekly flow report while the review is under way, a spokesperson said.

The fund data provider said it was reviewing the transaction to determine whether the reported movement reflected a transfer or another operational event.

On Friday Lipper data showed that U.S. investment-grade bond funds recorded $7.1 billion in net outflows during the week, the largest weekly withdrawal on record, after suffering a record one-day outflow of $8.2 billion on July 20.

Excluding the fund under review, U.S. investment-grade funds posted net inflows of $1.54 billion in the week ended July 22, according to a Bloomberg News report on Friday.

(Reporting by Mrinmay Dey in Mexico City, Editing by Louise Heavens)