The company said it was launching two new Walkman music phones and two Cybershot digital camera phones as well as the four low-end phones.
The low-cost phones, with color screens and two of which have a basic digital camera, will be available in the second quarter of 2007.
The company has a policy to sell devices with features and prices slightly above those of its competitors.
Sony Ericsson's head of Nordic operations, Johan Mathson, said he expected the four basic phones to sell somewhere between 50 and 100 euros, well above models priced as low as $30 and $40 from Motorola.
European head of marketing Ben Duffy said Sony Ericsson would not go as low as $40 at the launch.
Sony Ericsson said in statements on Tuesday it has sold 20 million Walkman phones to date and 4.5 million Cybershot phones since the recent introductions.
While Sony Ericsson has focused mainly on the segment of higher value phones, its bigger rivals Nokia , Motorola and Samsung battled it out in emerging markets with low-cost phones, pushing down the average price per phone and in the cases of Motorola and Samsung also resulting in lower profit margins.
Sony Ericsson, which is now the second-most profitable phone maker behind Nokia as a result of its focus on expensive, high-margin phones, has said it will no longer stay on the sidelines in this battle and that it wants to become the world's third biggest mobile phone vendor.