While Lumia 640 XL will begin rolling out globally in March, Lumia 640 will be available starting April. Both the devices will be available in single-SIM and dual-SIM (3G & 4G) variants.
"Pricing will vary by market and operator. Lumia 640 is estimated to be around 139 euros (about Rs 9,700) for the 3G model and 159 euros (about Rs 11,000) for the LTE model, before taxes and subsidies.
"Lumia 640 XL will be around 189 euros (about Rs 13,000) for 3G and 219 euros (about Rs 15,200) for LTE, before taxes and subsidies," Microsoft Devices Group Executive Vice President Stephen Elop said.

Both smartphones are upgradeable to Windows 10, which will be available later this year.
"The devices come with a one-year personal subscription to Office365, enabling the full Office experience on the Lumia as well as one tablet and one PC/Mac. The subscription also include one terabyte of storage on OneDrive – that's essentially unlimited storage for most people," he said.
The Lumia 640 comes with 5-inch HD display, 1.2GHz quad core Qualcomm Snapdragon processor, Windows Phone 8.1 with Lumia Denim operating system, 8 MP rear and 1 MP front facing cameras, 8GB internal memory (30 GB free OneDrive and micro SD support up to 128 GB) and 2,500 mAh battery.
The Lumia 640 XL has a 5.7-inch display, 13 MP rear and 5 MP front cameras and 3,000 mAh battery.

Microsoft also introduced a super-lightweight universal keyboard that works with iPads, iPhones, Android devices, and Windows tablets.
Windows OS is the world's third most widely used mobile operating system, after Google's Android and Apple iOS, with 2.7 per cent share of the global smartphone market as per research firm IDC.
Nokia had lost a considerable part of its handset market share to rivals Samsung and Apple as it struggled to position itself among the fast changing needs of consumers.