The British bank has narrowed the list of bidders to McGraw Hill Financial Inc's S&P Dow Jones Indices and Markit after an auction that also drew interest from several parties including MSCI Inc and Bloomberg LP, the people said on Tuesday.

Barclays, which launched the long-anticipated auction of its Index, Portfolio and Risk Solutions (IPRS) business this summer, could conclude the process within weeks, the people added, asking not to be named because the matter is private.

The business includes a basket of more than 98 major indexes, according to the unit's website.

Before Barclays provided detailed financial information on the index business, potential bidders estimated the unit to be worth several hundred million dollars.

But the business showed higher than expected revenue figures and the competition for the asset has proved robust, driving the price tag to more than $1 billion recently, the sources said.

Representatives for Barclays, Markit and S&P declined to comment. S&P is owned by McGraw Hill Financial Inc.

With investors pouring billions of dollars into passively managed funds, more firms are looking to broaden their index-based offerings. In January, S&P Dow Jones Indices Chief Executive Alex Matturri told Reuters it was interesting looking at bidding on index businesses that come to market, including the index businesses run by Russell and Barclays..

Barclays' U.S. Aggregate Bond Index, which the bank bought as part of the Lehman Brothers acquisition during the financial crisis, is among the platform’s best-known offerings.

In addition, the Barclays business includes a risk solutions software tool used by institutional investors to perform analysis of their holdings.

Reuters first reported in November that Barclays began exploring options for the index business following an approach from MSCI.

Earlier this year, Northwestern Mutual Life Insurance Company [NMLIC.UL] also ran a competitive process to find a buyer for its index businesses, Russell Investments. London Stock Exchange Group Plc bought Russell, the creator of the well-known Russell 1000 Global Index, for $2.7 billion in cash.

(Reporting by Mike Stone and Jessica Toonkel in New York; editing by Matthew Lewis and David Gregorio)

By Mike Stone and Jessica Toonkel