LONDON (Reuters) - Luxury British carmaker Aston Martin has cut the upper end of its initial public offering price range to 20 pounds per share, giving it a potential market value of up to 4.6 billion pounds ($6 billion), following mixed feedback from investors.

Aston Martin had initially set a range of 17.50 pounds to 22.50 pounds per share, but said on it Monday it had narrowed this to 18.50 pounds to 20 pounds and that it had enough bid interest to cover all the shares being sold at this level.

“Feedback was mixed,” said one person familiar with the deal saying investors were worried about the execution of the roll out of new models but were impressed by the management.

“Bottom of the range is the only level that might work.”

Aston Martin, famed for making the sports car driven by fictional secret agent James Bond, said it expected to close the IPO books at midday London time on Tuesday.

Bankers say that IPOs generally need twice as many bids as shares on offer to be successful.

Several multi-billion European IPOs got off to a cautious start last week when crowd-lending platform Funding Circle FCH.L traded down on its debut while Swiss packaging company SIG Combibloc SIGNC.S booked gains.

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On Monday, German brake systems maker Knorr-Bremse also said it had attracted bids for all shares on offer in its initial public offering planned for later this month.

Based on around 57 million shares being sold, a free float of 25 percent, the listing would give the company a market capitalization of up to around 4.6 billion pounds.

Depending on where it prices within the range, Aston Martin may just make it into the FTSE 100 after its flotation and will be the first car maker in the blue-chip index since Jaguar.

The company is selling around 25 percent of its stock in the first IPO by a British carmaker for decades.

The flotation follows a sale of shares by its main owners, Kuwaiti and Italian private equity groups.