SAN FRANCISCO - Sony's ( SNE) latest PlayStation 3 console has stretched its lead over rival Microsoft's ( MSFT) Xbox 360 last month, though it still lags behind Nintendo's Wii system, according to industry research firm The NPD Group. Sony sold 405,500 PS3s, compared to 219,800 Xbox 360s but still has a long way to go before it catches up with the Wii, which sold 666,700 systems last month. It's the second month that the PS3 has stayed ahead of the Xbox 360. Sony still has a long way to go before it beats Nintendo. The Nintendo Wii has now become the best-selling console among its peers, with 10.9 million units sold year-to-date in the U.S. Sony stumbled when it launched the expensive PS3 console a year-and-a-half ago and trailed its competitors for months. That's in contrast to its position as the clear market leader with the older PlayStation 2 console. Sony is making concerted efforts to regain its footing. Earlier this week, it shaved $100 off the price of the PS3. Sony said the 80-gigabyte version of the PS3 will retail at $400, down from $500, while discontinuing the 40-GB version of the console. Microsoft also dropped $50 off the price of the Xbox 360 and said the basic 20-GB model of the console will retail at $299. Sales of PlayStation 3 were helped by Konami's ( KNM) latest release, Metal Gear Solid 4: Gun of The Patriots for the PS3, which zoomed to the top of the charts with nearly 775,000 copies sold last month. Konami's game was made exclusively available on the PS3.