On Tuesday, Ziggo said private equity firms Cinven and Warburg Pincus had sold a 20 percent stake in the company, which floated in Amsterdam a year ago.

Barclays disclosed its holding to Dutch market regulator AFM on Friday in a filing published on the regulator's website, as is required by shareholders when their stake in a company goes above 5 percent.

That 14.2 percent would comprise Ziggo shares held across all parts of the bank's business, including any it might have already held before the placing.

At the 25.05 euros per share Tuesday's offer was priced at, a 14.2 percent stake would have cost Barclays around 713 million euros ($920 million).

Shares in Ziggo were trading at 24.3 euros by 1054 GMT on Friday, 3.36 percent down on the day.

Bankers at rival firms said many investment banks had bid to run the sale, but Barclays, which was not involved in Ziggo's listing or the private equity groups' previous sell downs, had offered the company a higher price than the others.

While running such bloc placings of shares do not tend to generate large fees for bookrunners, they can help boost a bank's position in investment banking league tables.

Based on the March 15 Thomson Reuters European equity capital markets league tables, the latest available, the 1 billion euro Ziggo sale would have almost doubled Barclays deal volume so far this year and moved it up two rungs from eighth to sixth, assuming rivals' deal volumes remained unchanged.

It is not the first time a bank has had to declare a stake following a placing. In November last year HSBC disclosed a 5.4 percent holding in Spain's Amaedus after running a share sale for the travel technology company.

Barclays declined to comment. ($1 = 0.7737 euros)

(Reporting by Kylie MacLellan)

Stocks treated in this article : Amadeus IT Holding SA, Barclays PLC, HSBC Holdings plc, ZIGGO