VNU NV, the Dutch owner of the ACNielsen research company, is discussing an $8.88 billion bid from buyout firms including Kohlberg Kravis Roberts & Company, two months after shareholders forced the resignation of VNU’s chief executive.

VNU said it received an offer of $34 to $34.52 a share from a group that also includes AlpInvest Partners NV, Blackstone Group LP, Carlyle Group, Hellman & Friedman LLC, Permira Advisers Ltd., and Thomas H. Lee Partners LP.VNU declined 35 cents to $33.79 in Amsterdam.

“A bid for VNU was only a question of time, though the level of this bid seems to be a bit meager,” said Maurits Heldring, an analyst at Kepler Equities in Amsterdam, who had estimated a bid could reach between $36.33 and $38.75.

VNU has been vulnerable to a takeover since November, when it scrapped a $6.3 billion acquisition of IMS Health Inc. and Chief Executive Officer Rob van den Bergh said he would quit after institutional shareholders objected to the purchase. The Haarlem, Netherlands-based company said last month it had received “more than one approach,” declining to name the bidders.

VNU said yesterday it’s only talking with the buyout group after gauging the “level of interest of certain other parties.” The bid was made “after several weeks of diligence and access to VNU management,” the company said. VNU said it expects to provide more information within three or four weeks.

A buyout group probably would sell the VNU Business Information division that publishes magazines and organizes trade shows, said analysts including Hans Slob of Rabobank Securities in Amsterdam.

“This part of the VNU business is already very lean and mean, so there’s not a lot of room for cost saving,” he said. Possible buyers might include United Business Media Plc and Reed Elsevier, he said.

A UBM spokesman, Chris Barrie, declined to comment, as did Reed Elsevier’s Patrick Kerr.

The participation of many major buyout firms in the bid lessens the possibility of a competing offer, said stockbrokers Petercam. The group “may have to increase its bid slightly” to satisfy VNU’s large institutional shareholders including Fidelity Investments, Templeton Global Advisors Ltd., and Knight Vinke Asset Management LLC, said Mr. Slob at Rabobank.

Knight Vinke, which holds about 2% of VNU, said in a statement yesterday that shareholders “require a better understanding” of the earnings potential of VNU’s individual businesses before concluding what those units are worth. Knight Vinke in December appointed a management consultant to study VNU’s businesses, and the findings will be presented to the VNU board. Knight Vinke expects to make a further announcement next week, it said.

Shares in VNU reached a two-year intraday high of $35.61 on December 14, after the company said it had received more than one bid.

The annual insurance cost for VNU bond payments rose to a record following the buyout offer, which is likely to be mostly funded by debt. The yearly cost of insuring payment on $12 million of VNU bonds using credit-default swaps rose to 250 basis points, or $302,755, from $272,475 on Friday, according to Deutsche Bank AG prices yesterday.

Private-equity firms raised at least $115 billion for acquisitions last year, and they’re increasingly joining together to take on larger targets such as VNU, which owns Billboard magazine as well as ACNielsen for retail research and Nielsen Media Research for television audience ratings.

The combination of record funds and cheap debt helped firms to make $118 billion of buyouts in Europe last year, a 37% increase on 2004. VNU is the biggest buyout announced so far in 2006.

Blackstone, KKR, and Permira were among a group of firms that in November agreed to buy Danish phone company TDC A/S for $15.3 billion in Europe’s biggest leveraged buyout.

KKR is spending a $5.45 billion European fund it raised in October, while Blackstone, also based in New York, is close to raising more than $12.5 billion for the world’s biggest buyout fund.

AlpInvest, based in Amsterdam, is Europe’s largest investor in private equity funds, with $36.3 billion under management.

Washington-based Carlyle Group is investing a $2.2 billion European buyout fund it raised last year. Thomas H. Lee Partners LP is preparing to raise an $8 billion buyout fund, its biggest since the Boston-based firm started in 1974.

Permira is based in London and Hellman & Friedman has its main office in San Francisco.