At the moment, BT users can use BT Communicator to place VoIP calls. However, BT plans to halve the cost of its Voice over IP service from October 4, as it looks to counter the increased popularity of rival offerings from VoIP pioneer Skype Technologies SA, which was recently acquired by the online auctioneer eBay Inc for $2.6bn. Other players such as Vonage Holdings Corp, and the recently launched VoIP product Freetalk from UK electronics retailer Dixons, are also starting to make their presence known, as are the countless other VoIP offerings from the likes of Google, AOL, Microsoft, and Yahoo.

The cost of BT’s VoIP calls to 30 countries such as the US, Australia, Spain, and France will cost just 5 pence (8 cents) a minute. For example, a 60-minute call to a US landline, which would cost 72p ($1.27) with Skype, would cost 30p ($0.53) with BT, said the telco in a statement. However, it should be remembered that Skype calls to other Skype users are free of charge, regardless of location. BT is comparing the price of a Skype call to a foreign landline.

BT’s offer only runs until December 31 and it is not clear whether BT will extend the deal after that date. Currently, the carrier offers calls to Australia with no call charges for up to one hour with BT Communicator with Yahoo! Messenger.

Another advantage of the BT offering is that with BT Communicator, the cost is charged to a customer’s usual BT phone bill, whereas with Skype, customers have to buy pre-paid credit.

We were the first telecoms company to offer voice over internet two years ago and we intend to keep ahead of the game, said Gavin Patterson, BT group managing director, Consumer. There’s been a lot of hype about Skype, but these international calls are half their price. We are not going to sit back while competitors lure our customers with cheap internet calls. We will fight for every customer by offering our own attractive prices for these calls. And with BT Communicator you can make the same call at a BT Openzone hotspot when you are out and about.

He continued: Unlike traditional telephony, where we are heavily regulated, for internet telephony we can compete on an equal basis and offer customers the same advantages of low cost calls over the internet, but from a global, trusted brand.

While it is true that BT has had VoIP for a while now, it hasn’t really made much of an impact compared to the huge growth of players such as Skype. BT Communicator only has 50,000 users, and when you compare this to Skype, which boasts an impressive 151 million downloads of the software plus an active on-net user base of 54 million people, you can see the size of the task BT is facing.

Skype has 2 million premium customers taking paying services such as SkypeOut (PSTN break-out) and SkypeIn (a phone number that can be called from regular phones). The company is attracting 150,000 new users per day, and is expected to have a customer base of 57 million by the end of the quarter.

In separate news, the UK ISP Plusnet is to launch its VoIP service this week. Calls between Plusnet users will be free and there will be a charge of 3.99 pounds ($7.05) a month for up to 3,000 minutes to all other numbers.