U.K. bank Barclays PLC (BCS) said Monday it has received additional proposals for its iShares business and the broader Barclays Global Investors unit that owns it, including from BlackRock Inc. (BLK).

The announcement is potentially a further challenge to CVC Capital Partners' deal agreed in April to buy iShares for $4.4 billion. The agreement allowed Barclays to shop around for better offers till the middle of June.

Barclays has said since that it has received other proposals for iShares and for BGI.

The announcement Monday comes after recent media reports said BlackRock and Bank of New York Mellon Corp (BK) are racing to buy BGI. The Financial Times said on Monday that BNY Mellon could challenge BlackRock's bid for BGI.

Pensions & Investments on Friday cited a person not directly involved in the deal as saying that the announcement was likely "within the next few days."

Another person said that, although CVC would have the option to counteroffer, its chances of topping the BlackRock offer, said to be in excess of $10 billion, would be slim.

"In assessing such proposals, Barclays has had discussions with a number of parties, including with BlackRock, about both iShares and BGI," it said Monday.

Barclays said "the discussions are not yet concluded and there are a number of significant open issues which could affect the nature and terms of any transaction."

"There is no certainty that these discussions will result in Barclays concluding a different transaction than that announced on April 9 with CVC regarding iShares," it said.

At 0742 GMT, Barclays shares were down 2.4% at 278 pence, while the FTSE100 index was down 1.1%.

Oriel Securities analyst Mike Trippitt said a bidding war for BGI is now possible as there are other parties interested in the asset.

He said that based on media reports, "it reads like BlackRock is more advanced in organizing its finance, and that's something that Barclays might want to think about."

Shore Capital analyst Danny Clarke said that multiple proposals to buy BGI "suggest a competitive process which is encouraging for Barclays."

Clarke said that expectations of any deal being imminent could be dampened as Barclays said "significant open issues" could affect any transaction. "We still expect the sale of BGI to proceed, providing a further welcome boost to capital," Clarke said, while keeping his hold rating.

A Barclays spokesman said the company wouldn't comment beyond Monday's statement. A BNY Mellon spokesman couldn't be immediately contacted.

Company Web site: www.barclays.com

-By Vladimir Guevarra, Dow Jones Newswires. +44 (0) 20 7842 9486, vladimir.guevarra@dowjones.com